Control circuit for a display apparatus

ABSTRACT

A control circuit for a display apparatus is provided and includes a buffer configured to temporarily store therein externally-supplied image data; and a controller configured to output pixel signals to signal lines of the display apparatus based on the image data stored in the buffer and read detection signals generated in detection conductors which extend along the signal lines of the display apparatus due to the pixel signals.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of U.S. patentapplication Ser. No. 16/735,138 filed on Jan. 6, 2020, which is aDivisional Application of U.S. patent application Ser. No. 15/885,251filed on Jan. 31, 2018, and issued as U.S. Pat. No. 10,551,953 on Feb.4, 2020, which claims priority from Japanese Application No.2017-018579, filed on Feb. 3, 2017 and Japanese Application No.2017-171475, filed on Sep. 6, 2017, the contents of which areincorporated by reference herein in its entirety.

BACKGROUND 1. Technical Field

The present invention relates to a display apparatus.

2. Description of the Related Art

With the development of automatic driving technologies, vehicles havebeen expected to have higher comfortability in their indoor spaces. As aresult, there have been developed a larger number of onboard displaydevices, such as head-up displays (HUD), digital mirrors, and centerinformation displays (CID). International Organization forStandardization (ISO) 26262, which is a safety standard for electroniccontrol systems of vehicles, defines Automotive Safety Integrity Level(ASIL) indicating the risk classification for electronic control systemsof vehicles. Ensuring the safety of onboard display devices will be animportant matter.

Japanese Patent Application Laid-open Publication No. 2009-276612(JP-A-2009-276612) describes a liquid crystal display device that candetect abnormality.

There is a need for a display apparatus and a display apparatus with atouch detection function capable of detecting that an image is notappropriately displayed.

SUMMARY

According to an aspect, a display apparatus includes: a plurality ofpixels configured to display an image; a plurality of signal linesconfigured to supply pixel signals to the pixels; a plurality ofdetection conductors configured to be capacitively coupled to the signallines; and a controller configured to output the pixel signals to thesignal lines and read detection signals generated in the detectionconductors due to the pixel signals.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of the configuration of a display apparatusaccording to a first embodiment;

FIG. 2 is a diagram of the module configuration of the display apparatusaccording to the first embodiment;

FIG. 3 is a circuit diagram of pixels in a display device of the displayapparatus according to the first embodiment;

FIG. 4 is a schematic diagram of a sectional structure of a panel of thedisplay apparatus according to the first embodiment;

FIG. 5 is a diagram of the configuration of a horizontal driver and adrive electrode driver of the display apparatus according to the firstembodiment;

FIG. 6 is a diagram of a display area of the display apparatus accordingto the first embodiment;

FIG. 7 is a diagram of an operating sequence in a first exemplaryoperation performed by the display apparatus according to the firstembodiment;

FIG. 8 is a diagram of an operating timing in the first exemplaryoperation performed by the display apparatus according to the firstembodiment;

FIG. 9 is another diagram of the operating timing in the first exemplaryoperation performed by the display apparatus according to the firstembodiment;

FIG. 10 is a flowchart of an operation in the first exemplary operationperformed by the display apparatus according to the first embodiment;

FIG. 11 is a graph of an example of the relation between a detectionsignal and detection image data;

FIG. 12 is a diagram of an operating timing in a second exemplaryoperation performed by the display apparatus according to the firstembodiment;

FIG. 13 is a flowchart of an operation in the second exemplary operationperformed by the display apparatus according to the first embodiment;

FIG. 14 is a schematic diagram of a sectional structure of a panel of adisplay apparatus according to a modification of the first embodiment;

FIG. 15 is a diagram of the module configuration of a display apparatusaccording to a second embodiment;

FIG. 16 is a schematic diagram of a sectional structure of a panel ofthe display apparatus according to the second embodiment;

FIG. 17 is a diagram of the configuration of the horizontal driver andthe drive electrode driver of the display apparatus according to thesecond embodiment;

FIG. 18 is a diagram of an operating timing in an exemplary operationperformed by the display apparatus according to the second embodiment;

FIG. 19 is a diagram of the module configuration of a display apparatusaccording to a third embodiment;

FIG. 20 is a schematic diagram of a sectional structure of a panel ofthe display apparatus according to the third embodiment;

FIG. 21 is a diagram of the configuration of the horizontal driver, thedrive electrode driver, and a COF of the display apparatus according tothe third embodiment;

FIG. 22 is a diagram of the module configuration of a display apparatusaccording to a fourth embodiment;

FIG. 23 is a schematic diagram of a sectional structure of a panel ofthe display apparatus according to the fourth embodiment;

FIG. 24 is a diagram of the configuration of the horizontal driver, thedrive electrode driver, and the COF of the display apparatus accordingto the fourth embodiment;

FIG. 25 is a diagram of an operating timing in an exemplary operationperformed by the display apparatus according to the fourth embodiment;

FIG. 26 is a schematic diagram of a sectional structure of a panel ofthe display apparatus according to a modification of the fourthembodiment;

FIG. 27 is a block diagram of the configuration of a display apparatusaccording to a fifth embodiment;

FIG. 28 is a diagram of the module configuration of the displayapparatus according to the fifth embodiment;

FIG. 29 is a diagram of the configuration of a light emitter of thedisplay apparatus according to the fifth embodiment;

FIG. 30 is a schematic diagram of a first example of a sectionalstructure of the display apparatus according to the fifth embodiment;

FIG. 31 is a schematic diagram of a second example of a sectionalstructure of the display apparatus according to the fifth embodiment;

FIG. 32 is a schematic diagram of a third example of a sectionalstructure of the display apparatus according to the fifth embodiment;

FIG. 33 is a schematic diagram of a first example of a sectionalstructure of the light emitter in the display apparatus according to thefifth embodiment;

FIG. 34 is a schematic diagram of a second example of a sectionalstructure of the light emitter in the display apparatus according to thefifth embodiment;

FIG. 35 is a schematic diagram of a third example of a sectionalstructure of the light emitter in the display apparatus according to thefifth embodiment;

FIG. 36 is a schematic diagram of a fourth example of a sectionalstructure of the light emitter in the display apparatus according to thefifth embodiment;

FIG. 37 is a block diagram of the configuration of a display apparatuswith a touch detection function according to a sixth embodiment;

FIG. 38 is a diagram of the module configuration of the displayapparatus with a touch detection function according to the sixthembodiment;

FIG. 39 is a diagram for explaining the basic principle of mutualcapacitance touch detection and illustrates a state where an object tobe detected is in contact with or in proximity to a touch detectionelectrode;

FIG. 40 is a diagram for explaining an example of an equivalent circuitin mutual capacitance touch detection;

FIG. 41 is a diagram of an example of waveforms of a drive signal and adetection signal in mutual capacitance touch detection;

FIG. 42 is a perspective view of an exemplary configuration of driveelectrodes and detection lines in the display apparatus with a touchdetection function according to the sixth embodiment;

FIG. 43 is a diagram of the configuration of the horizontal driver, thedrive electrode driver, and the COF of the display apparatus with atouch detection function according to the sixth embodiment;

FIG. 44 is a diagram of an operating sequence in an exemplary operationperformed by the display apparatus with a touch detection functionaccording to the sixth embodiment;

FIG. 45 is a diagram of an operating timing in an exemplary operationperformed by the display apparatus with a touch detection functionaccording to the sixth embodiment;

FIG. 46 is another diagram of the operating timing in the exemplaryoperation performed by the display apparatus with a touch detectionfunction according to the sixth embodiment;

FIG. 47 is a flowchart of an operation in an exemplary operationperformed by the display apparatus according to the sixth embodiment;

FIG. 48 is a diagram of the configuration of the horizontal driver, thedrive electrode driver, and the COF of a display apparatus with a touchdetection function according to a seventh embodiment;

FIG. 49 is a diagram for explaining the basic principle ofself-capacitance touch detection and illustrates a state where an objectto be detected is neither in contact with nor in proximity to adetection electrode;

FIG. 50 is a diagram for explaining the basic principle ofself-capacitance touch detection and illustrates a state where an objectto be detected is in contact with or in proximity to the detectionelectrode;

FIG. 51 is a diagram for explaining an example of an equivalent circuitin self-capacitance touch detection;

FIG. 52 is a diagram of an example of waveforms of a drive signal and adetection signal in self-capacitance touch detection;

FIG. 53 is a diagram of the module configuration of a display apparatuswith a touch detection function according to an eighth embodiment;

FIG. 54 is a diagram of the configuration of the horizontal driver, thedrive electrode driver, and the COF of the display apparatus with atouch detection function according to the eighth embodiment;

FIG. 55 is a block diagram of the configuration of a display apparatuswith a touch detection function according to a ninth embodiment; and

FIG. 56 is a diagram of the module configuration of the displayapparatus with a touch detection function according to the ninthembodiment.

DETAILED DESCRIPTION

Exemplary aspects (embodiments) to embody the present invention aredescribed below in greater detail with reference to the accompanyingdrawings. The contents described in the embodiments are not intended tolimit the present invention. Components described below includecomponents easily conceivable by those skilled in the art and componentssubstantially identical therewith. Furthermore, the components describedbelow may be appropriately combined. What is disclosed herein is givenby way of example only, and appropriate modifications made withoutdeparting from the spirit of the invention and easily conceivable bythose skilled in the art naturally fall within the scope of theinvention. To simplify the explanation, the drawings may possiblyillustrate the width, the thickness, the shape, and other elements ofeach unit more schematically than the actual aspect. These elements,however, are given by way of example only and are not intended to limitinterpretation of the invention. In the present specification and thefigures, components similar to those previously described with referenceto previous figures are denoted by the same reference numerals, andoverlapping explanation thereof may be appropriately omitted.

In this disclosure, when an element is described as being “on” anotherelement, the element can be directly on the other element, or there canbe one or more elements between the element and the other element.

Japanese Patent Application Laid-open Publication No. 2009-276612(JP-A-2009 276612) describes a liquid crystal display device that candetect abnormality.

There is a need for a display apparatus and a display apparatus with atouch detection function capable of detecting that an image is notappropriately displayed.

1. First Embodiment

FIG. 1 is a block diagram of the configuration of a display apparatusaccording to a first embodiment.

A display apparatus 1 according to the present embodiment includes apanel PNL, a light emitter BL, and a controller CTL. The panel PNLincludes a display device DSP and a detector DET. The display device DSPdisplays an image. The detector DET detects an image.

The light emitter BL is disposed in an opposite direction of aZ-direction with respect to the panel PNL. The light emitter BL outputslight L in the Z-direction to irradiate the panel PNL.

The display device DSP receives the light L output from the lightemitter BL to display an image IMG in the Z-direction. The displaydevice DSP is a transmissive liquid crystal display apparatus, forexample, but is not limited thereto. The display device DSP may be atransflective liquid crystal display apparatus, a reflective liquidcrystal display apparatus, or an organic electroluminescence (EL)display apparatus. In a case where the display device DSP is areflective liquid crystal display apparatus or an organic EL displayapparatus, the light emitter BL is not necessarily provided.

The detector DET electrically detects the image IMG displayed by thedisplay device DSP. Specifically, the detector DET includes detectionlines capacitively coupled to signal lines that supply pixel signals topixels in the display device DSP. The detector DET generates detectionsignals in the detection lines due to the pixel signals.

The display apparatus 1 according to the present embodiment has an imagedisplay period for displaying an image and an image detection period fordetecting an image. The display apparatus 1 according to the presentembodiment employs a column inversion driving method of inverting thepolarity of image signals alternately in columns (pixel columns)adjacent to each other, which will be described later. Thus, the imagedetection period includes a period for detecting a positive-polarityimage and a period for detecting a negative-polarity image.

The display device DSP and the detector DET may be provided as anin-cell apparatus in which the display device DSP and the detector DETare integrated. Alternatively, the display device DSP and the detectorDET may be provided as an on-cell apparatus in which the detector DET ismounted on the display device DSP.

The controller CTL includes a display controller 2 and a detectioncontroller 3. The display controller 2 controls the display device DSPand the light emitter BL. The detection controller 3 reads detectionsignals from the detector DET and outputs detection image data to a hostHST based on the detection signals.

The display controller 2 is an integrated circuit (IC) chip mounted on aglass substrate of the display device DSP, for example. The detectioncontroller 3 is an IC chip mounted on printed circuits (e.g., flexibleprinted circuits) coupled to the glass substrate of the display deviceDSP, for example. The display controller 2 and the detection controller3 cooperate to control the display device DSP and the detector DET. Thedisplay controller 2 outputs timing signals each indicating an imagedetection timing to the detection controller 3.

The host HST outputs image data for displaying the image IMG to thecontroller CTL. The host HST compares the image data with the detectionimage data based on the detection signals, thereby determining whetherthe image IMG is normally displayed. The host HST is a centralprocessing unit (CPU), for example. The host HST may be included in thecontroller CTL.

Communications between the host HST, the display controller 2, and thedetection controller 3 are performed by Inter-Integrated Circuit (I²C)or Serial Peripheral Interface (SPI), for example.

The following describes a specific exemplary configuration of thedisplay device DSP and the detector DET. The exemplary configuration isgiven by way of example only, and the embodiment is not limited thereto.

FIG. 2 is a diagram of the module configuration of the display apparatusaccording to the first embodiment.

The panel PNL includes a substrate 4, a chip on glass (COG) 11 servingas a driver IC, and a chip on flexible (COF) 12 serving as a detectionIC.

The substrate 4 includes a first substrate 5 and a second substrate 6.The second substrate 6 is disposed in the Z-direction with respect tothe first substrate 5 and faces the first substrate 5 with apredetermined space interposed therebetween.

The substrate 4 has a display area DA and a peripheral area GD. In thedisplay area DA, a plurality of pixels Pix including liquid crystalelements are disposed in a matrix (row-column configuration). Theperipheral area GD is positioned outside the display area DA. Theperipheral area GD is provided with a vertical driver (vertical drivecircuit) 7, a horizontal driver (horizontal drive circuit) 8, and adrive electrode driver 9.

The COG 11 is mounted on the first substrate 5 and controls the verticaldriver 7, the horizontal driver 8, and the drive electrode driver 9.

The COF 12 is mounted on flexible printed circuits (FPC) T coupled tothe first substrate 5.

The COG 11 and the COF 12 are coupled to the host HST (refer to FIG. 1)via the FPC T. The COG 11 includes a buffer 11 a that temporarily storestherein image data supplied from the host HST.

The first substrate 5 is provided with a plurality of pixel circuitsincluding active elements (e.g., transistors) and disposed in a matrix(row-column configuration). The second substrate 6 is disposed facingthe first substrate 5 with a predetermined space interposedtherebetween. The space between the first substrate 5 and the secondsubstrate 6 is maintained by photospacers disposed at respectivepositions on the first substrate 5 to have a predetermined size. Thespace between the first substrate 5 and the second substrate 6 is filledwith liquid crystals. The positions and the sizes of the componentsillustrated in FIG. 2 are schematic ones and do not reflect the actualpositions, for example.

The display area DA has a matrix (row-column) configuration in which thepixels Pix are arrayed in M-rows and N-columns. In the presentspecification, a row means a pixel row including N pixels Pix arrayed inan X-direction. A column means a pixel column including M pixels Pixarrayed in a Y-direction orthogonal to the extending direction of therow. M and N are determined based on the display resolution in thevertical direction and that in the horizontal direction, respectively.Examples of the array of the pixels Pix include, but are not limited to,480 rows×640 columns, 720 rows×1280 columns, 1080 rows×1920 columns,etc.

The display area DA is provided with scanning lines GL and signal linesSL. The scanning lines GL are provided for the respective rows in thearray of M×N pixels Pix and extend in the X-direction. The signal linesSL are provided for the respective columns and extend in theY-direction. In other words, the number of scanning lines GL is M, andthe number of signal lines SL is N.

The display area DA is also provided with drive electrodes COML. Thedrive electrodes COML extending in the Y-direction are arranged one forevery two columns of the pixels Pix. In other words, the number of driveelectrodes COML is (N/2). The configuration described above is given byway of example only, and the drive electrodes COML are not necessarilyarranged one for every two columns of the pixels Pix.

The display area DA is also provided with detection lines RL. Thedetection lines RL extending in the Y-direction are arranged one forevery two columns of the pixels Pix such that the detection lines RLcorrespond to the respective drive electrodes COML. In other words, thenumber of detection lines RL is (N/2). The configuration described aboveis given by way of example only, and the detection lines RL are notnecessarily arranged one for every two columns of the pixels Pix.

The COG 11 outputs horizontal synchronization signals and verticalsynchronization signals to the vertical driver 7, the horizontal driver8, and the drive electrode driver 9.

The vertical driver 7 latches digital data output from the COG 11 inunits of one horizontal period in synchronization with the verticalsynchronization signals and the horizontal synchronization signals. Thevertical driver 7 outputs the latched digital data of one line in orderas vertical scanning pulses. The vertical driver 7 sequentially suppliesthe vertical scanning pulses to the scanning lines GL in the displayarea DA, thereby sequentially selecting the pixels Pix row by row. Thevertical driver 7 outputs the digital data in order from the upper partin the vertical scanning direction in the display area DA to the lowerpart in the vertical scanning direction in the display area DA, forexample. The lower part is located in the Y-direction with respect tothe upper part. Alternatively, the vertical driver 7 may output thedigital data in order from the lower part in the vertical scanningdirection in the display area DA, which is closer to the forward side inthe Y-direction, to the upper part in the vertical scanning direction inthe display area DA, which is closer to the opposite side in theY-direction, for example.

The horizontal driver 8 is supplied with 6-bit digital image data of R(red), G (green), and B (blue), for example, from the COG 11. Thehorizontal driver 8 writes pixel signals to the pixels Pix of the rowselected in vertical scanning performed by the vertical driver 7 via thesignal lines SL in units of a sub-pixel, in units of a plurality ofsub-pixels, or in one unit of all the sub-pixels.

The drive electrode COML is made of a transparent material and shared bythe pixels Pix of at least one column, for example. The drive electrodesCOML are coupled to the drive electrode driver 9. In the image displayperiod, the drive electrode driver 9 supplies constant drive signalsVCOM to the drive electrodes COML. In the image detection period, thedrive electrode driver 9 brings the drive electrodes COML into afloating state. In the image display period, the drive electrodes COMLgenerate an electric field for driving the liquid crystals between thedrive electrodes COML and pixel electrodes, which will be describedlater.

The COF 12 is coupled to the detection lines RL. The COF 12 outputsdetection image data to the host HST based on the detection signalsgenerated in the detection lines RL due to to the pixel signals. Thedetection lines RL according to the present embodiment are arranged onefor every two columns of the pixels Pix. In other words, the number ofpieces of detection pixel data in one line of the detection image datais (N/2). The configuration described above is given by way of exampleonly, and the detection lines RL are not necessarily arranged one forevery two columns of the pixels Pix. The detection lines RL may bearranged one for every one or every three or more columns of the pixelsPix.

The COG 11, the vertical driver 7, the horizontal driver 8, and thedrive electrode driver 9 correspond to the display controller 2illustrated in FIG. 1. The COF 12 corresponds to the detectioncontroller 3 illustrated in FIG. 1.

In the display apparatus 1, continuous application of a direct-current(DC) voltage of the same polarity to the liquid crystals may possiblydeteriorate resistivity (substance-specific resistance) or the like ofthe liquid crystals. To prevent deterioration in the resistivity(substance-specific resistance) or the like of the liquid crystals, thedisplay apparatus 1 employs a driving method of inverting the polarityof image signals with a predetermined cycle based on the commonpotential of the drive signals.

Some types of methods for driving a liquid crystal display apparatus areknown, including column inversion, line inversion, dot inversion, andframe inversion driving methods. The column inversion driving method isa driving method of inverting the polarity of image signals alternatelyin columns (pixel columns) adjacent to each other. The line inversiondriving method is a driving method of inverting the polarity of imagesignals on a cycle of 1H (H represents a horizontal period)corresponding to one line (one pixel row). The dot inversion drivingmethod is a driving method of inverting the polarity of image signalsalternately in pixels vertically and horizontally adjacent to eachother. The frame inversion driving method is a driving method ofinverting the polarity of video signals to be written to all the pixelsin one frame corresponding to one screen with the same polarity at atime. The display apparatus 1 may employ any one of the driving methodsdescribed above. The display apparatus 1 according to the presentembodiment employs the column inversion driving method.

FIG. 3 is a circuit diagram of pixels in the display device of thedisplay apparatus according to the first embodiment.

The pixels Pix each include a plurality of sub-pixels SPix. The displayarea DA is provided with signal lines SL_(n), SL_(n+1), and SL_(n+2) (nis a natural number) and scanning lines GL_(m), GL_(m+1), and GL_(m+2)(m is a natural number), for example. The signal lines SL_(n), SL_(n+1),and SL_(n+2) supply pixel signals serving as display data to thin filmtransistor (TFT) elements Tr in the respective sub-pixels SPix. Thescanning lines GL_(m), GL_(m+1), and GL_(m+2) drive the TFT elements Tr.As described above, the signal lines SL_(n), SL_(n+1), and SL_(n+2)extend on a plane parallel to a surface of the substrate 4 and supplythe pixel signals for displaying an image to the sub-pixels SPix.

The sub-pixels SPix each include the TFT element Tr, a pixel electrodePE, and a liquid crystal LC. The TFT element Tr is a thin filmtransistor, that is, an n-channel metal oxide semiconductor (MOS) TFT inthis example. One of the source and the drain of the TFT element Tr iscoupled to the signal line SL_(n), SL_(n+1), or SL_(n+2), the gatethereof is coupled to the scanning line GL_(m), GL_(m+1), or GL_(m+2),and the other of the source and the drain thereof is coupled to thepixel electrode PE. A first end of the liquid crystal LC is coupled tothe pixel electrode PE, and a second end thereof is coupled to the driveelectrode COML. Holding capacitance that holds the voltage between thepixel electrode PE and the drive electrode COML is provided in parallelwith the liquid crystal LC.

The sub-pixel SPix is coupled to the other sub-pixels SPix belonging tothe same row in the display area DA by the scanning line GL_(m),GL_(m+1), or GL_(m+2). The scanning lines GL_(m), GL_(m+1), and GL_(m+2)are coupled to the vertical driver 7 (refer to FIG. 2) and supplied withthe vertical scanning pulses of scanning signals from the verticaldriver 7. The sub-pixel SPix is also coupled to the other sub-pixelsSPix belonging to the same column in the display area DA by the signalline SL_(n), SL_(n+1), or SL_(n+2). The signal lines SL_(n), SL_(n+1),and SL_(n+2) are coupled to the horizontal driver 8 (refer to FIG. 2)and supplied with pixel signals from the horizontal driver 8. Thesub-pixel SPix is also coupled to the other sub-pixels SPix belonging tothe same column in the display area DA by the drive electrode COML. Thedrive electrodes COML are supplied with the drive signals VCOM from thedrive electrode driver 9 (refer to FIG. 2) in the image display period.The drive electrodes COML are brought into a floating state in the imagedetection period.

The vertical driver 7 illustrated in FIG. 2 applies the verticalscanning pulses to the gates of the TFT elements Tr of the respectivesub-pixels SPix via the scanning lines GL_(m), GL_(m+1), and GL_(m+2)illustrated in FIG. 3. The vertical driver 7 thus sequentially selectsone row (one horizontal line) out of the sub-pixels SPix arranged in amatrix (row-column configuration) in the display area DA as a target ofdisplay drive. The horizontal driver 8 illustrated in FIG. 2 suppliesthe pixel signals to the respective sub-pixels SPix included in onehorizontal line sequentially selected by the vertical driver 7 via thesignal lines SL_(n), SL_(n+1), and SL_(n+2) illustrated in FIG. 3. Withthese sub-pixels SPix, display of one horizontal line is performed basedon the supplied pixel signals.

As described above, the vertical driver 7 in the display apparatus 1drives the scanning lines GL_(m), GL_(m+1), and GL_(m+2) to sequentiallyscan each of the scanning lines GL_(m), GL_(m+1), and GL_(m+2), therebysequentially selecting one horizontal line. The horizontal driver 8 inthe display apparatus 1 supplies the pixel signals to the pixels Pixbelonging to the one horizontal line, thereby performing display of eachhorizontal line. To perform the display operation, the drive electrodedriver 9 applies the drive signals VCOM to the drive electrodes COML.

The display area DA includes a color filter. The color filter has colorareas of three colors (e.g., R (red), G (green), and B (blue)) or fourcolors corresponding to the respective sub-pixels SPix. In the colorfilter, a color area 22R colored in red (R), a color area 22G colored ingreen (G), and a color area 22B colored in blue (B) are periodicallyarrayed, for example. In a case where the fourth color is white (W), nocolor is provided for white (W) by the color filter. In a case where thefourth color is another color, the color employed as the fourth color isprovided by the color filter.

A set of the color areas 22R, 22G, and 22B in the three colors of R(red), G (green), and B (blue), that is, a set of the total three colorsmay be provided for one pixel Pix. Alternatively, a set of the colorareas 22R, 22G, and 22B in the three colors of R (red), G (green), and B(blue) and the fourth color (e.g., W), that is, a set of the total fourcolors may be provided for one pixel Pix. Still alternatively, a set ofareas colored in other colors may be provided for one pixel Pix. Thepixel signal for one pixel Pix according to the present embodiment is apixel signal corresponding to output of one pixel Pix including thesub-pixels SPix of red (R), green (G), and blue (B). In the descriptionof the present embodiment, red (R), green (G), and blue (B) may besimply referred to as R, G, and B. In a case where the pixels Pix eachinclude the sub-pixels SPix of two or less colors or five or morecolors, digital data corresponding to the number of colors is suppliedto the pixels Pix based on original image data.

The color filter may have a combination of other colors as long as theyare different colors. In typical color filters, the luminance of thecolor area 22G of green (G) is higher than that of the color area 22R ofred (R) and the color area 22B of blue (B). In a case where the fourthcolor is white (W), the color filter may be made of a light transmissiveresin to produce white.

FIG. 4 is a schematic diagram of a sectional structure of the panel ofthe display apparatus according to the first embodiment. FIG. 4 is aschematic diagram of a sectional structure of one pixel Pix.

The panel PNL is an in-cell apparatus in which the detector DET isintegrated with the display device DSP. Integrating the detector DETwith the display device DSP includes a case where part of members, suchas substrates and electrodes, for the display device DSP are also usedas part of members, such as substrates and electrodes, for the detectorDET, for example.

The panel PNL includes the first substrate 5, the second substrate 6,and the liquid crystal LC. The second substrate 6 faces the firstsubstrate 5. The liquid crystal LC is disposed between the firstsubstrate 5 and the second substrate 6.

The first substrate 5 includes a substrate 31 serving as a translucentinsulation substrate. The substrate 31 is a glass substrate, forexample, but is not limited thereto. A polarization plate 32 is disposedon a surface of the substrate 31 facing in the opposite direction of theZ-direction. The polarization plate 32 allows only polarizationcomponents having a certain polarization direction in the light L outputfrom the light emitter BL (refer to FIG. 1) to pass therethrough.

The scanning line GL serving as a first metal layer is provided on asurface of the substrate 31 facing in the Z-direction. The scanning lineGL extends in the X-direction (horizontal direction in FIG. 4). Aninsulation layer 33 is provided on the scanning line GL in theZ-direction. The TFT elements Tr (refer to FIG. 3), which are notillustrated in FIG. 4, may be provided between the scanning line GL andthe insulation layer 33.

Signal lines SL₁, SL₂, and SL₃ serving as a second metal layer areprovided on the insulation layer 33 in the Z-direction. The signal linesSL₁, SL₂, and SL₃ extend in the Y-direction (direction perpendicular tothe plane of FIG. 4). A planarization film 34 is provided on the signallines SL₁, SL₂, and SL₃.

The drive electrode COML serving as a first transparent conductive filmlayer is provided on a surface of the planarization film 34 facing inthe Z-direction. The drive electrode COML extends in the Y-direction(direction perpendicular to the plane of FIG. 4). The first transparentconductive film layer is made of indium tin oxide (ITO), for example,but is not limited thereto.

An insulation film 35 is provided on the drive electrode COML in theZ-direction. Pixel electrodes PE₁, PE₂, and PE₃ serving as a secondtransparent conductive film layer are provided on a surface of theinsulation film 35 facing in the Z-direction. The second transparentconductive film layer is made of ITO, for example, but is not limitedthereto.

The pixel electrodes PE₁, PE₂, and PE₃ each have a plurality of slitsextending in the Y-direction (direction perpendicular to the plane ofFIG. 4). An electric field is formed between each of the pixelelectrodes PE₁, PE₂, and PE₃ and the drive electrode COML via the slits.The electric field causes the molecules of the liquid crystal LC torotate about the Z-direction, thereby rotating the polarizationdirection of light having passed through the polarization plate 32. Inother words, the panel PNL is a fringe-field switching (FFS) liquidcrystal display apparatus, which is a kind of lateral electric fieldmode liquid crystal display apparatuses. The panel PNL is not limited toan FFS liquid crystal display apparatus and may be an in-plane switching(IPS) liquid crystal display apparatus.

The second substrate 6 includes a substrate 41 serving as a translucentinsulation substrate. The substrate 41 is a glass substrate, forexample, but is not limited thereto. The color area 22R colored in red(R), the color area 22G colored in green (G), and the color area 22Bcolored in blue (B) are provided on a surface of the substrate 41 facingin the opposite direction of the Z-direction. The detection line RL isprovided on a surface of the substrate 41 facing in the Z-direction. Thedetection line RL extends in the Y-direction (direction perpendicular tothe plane of FIG. 4). The detection line RL corresponds to the detectorDET illustrated in FIG. 1. A polarization plate 42 is disposed on thedetection line RL in the Z-direction. The polarization plate 42 allowsonly polarization components having a certain polarization direction inthe light having passed through the liquid crystal LC to passtherethrough. A translucent cover member 44 is disposed in theZ-direction with respect to the polarization plate 42. The cover member44 is made of a glass or a resin, for example.

FIG. 5 is a diagram of the configuration of the horizontal driver andthe drive electrode driver of the display apparatus according to thefirst embodiment. FIG. 5 illustrates a portion of the horizontal driver8 that drives the pixels Pix of four columns and a portion of the driveelectrode driver 9 that drives the pixels Pix of four columns.

One pixel Pix according to the present embodiment includes threesub-pixels SPix. The signal line SL₁ supplies the pixel signals to thesub-pixels SPix of red (R) in the pixels Pix in the first column. Thesignal line SL₂ supplies the pixel signals to the sub-pixels SPix ofgreen (G) in the pixels Pix in the first column. The signal line SL₃supplies the pixel signals to the sub-pixels SPix of blue (B) in thepixels Pix in the first column.

A signal line SL₄ supplies the pixel signals to the sub-pixels SPix ofred (R) in the pixels Pix in the second column. A signal line SL₅supplies the pixel signals to the sub-pixels SPix of green (G) in thepixels Pix in the second column. A signal line SL₆ supplies the pixelsignals to the sub-pixels SPix of blue (B) in the pixels Pix in thesecond column.

A signal line SL₇ supplies the pixel signals to the sub-pixels SPix ofred (R) in the pixels Pix in the third column. A signal line SL₈supplies the pixel signals to the sub-pixels SPix of green (G) in thepixels Pix in the third column. A signal line SL₉ supplies the pixelsignals to the sub-pixels SPix of blue (B) in the pixels Pix in thethird column.

A signal line SL₁₀ supplies the pixel signals to the sub-pixels SPix ofred (R) in the pixels Pix in the fourth column. A signal line SL₁₁supplies the pixel signals to the sub-pixels SPix of green (G) in thepixels Pix in the fourth column. A signal line SL₁₂ supplies the pixelsignals to the sub-pixels SPix of blue (B) in the pixels Pix in thefourth column.

The drive electrodes COML according to the present embodiment arearranged one for every two columns of the pixels Pix. A drive electrodeCOML₁ supplies the drive signals VCOM to the pixels Pix in the first andthe second columns. A drive electrode COML₂ supplies the drive signalsVCOM to the pixels Pix in the third and the fourth columns.

The detection lines RL according to the present embodiment are arrangedone for every two columns of the pixels Pix such that the detectionlines RL correspond to the respective drive electrodes COML. A detectionline RL₁ is capacitively coupled to the signal lines SL₁ to SL₆ togenerate a detection signal due to to the pixel signals supplied to thesignal lines SL₁ to SL₆. A detection line RL₂ is capacitively coupled tothe signal lines SL₇ to SL₁₂ to generate a detection signal due to tothe pixel signals supplied to the signal lines SL₇ to SL₁₂.

The horizontal driver 8 includes twelve amplifiers SIGAMP₁ to SIGAMP₁₂.One pixel Pix according to the present embodiment includes threesub-pixels SPix, that is, a sub-pixel SPix of red (R), a sub-pixel SPixof green (G), and a sub-pixel SPix of blue (B). The twelve amplifiersSIGAMP₁ to SIGAMP₁₂ output the pixel signals to the pixels Pix in fourcolumns, which is obtained by dividing 12 by 3. The present embodimentemploys a column inversion driving method of inverting the polarity ofimage signals alternately in columns (sub-pixel columns) adjacent toeach other. The amplifier SIGAMP₁ that outputs positive-polarity pixelsignals and the amplifier SIGAMP₂ that outputs negative-polarity pixelsignals are paired with each other. The output terminal of the amplifierSIGAMP₁ and the output terminal of the amplifier SIGAMP₂ are coupled toa switcher S₁. The switcher S₁ couples the amplifier SIGAMP₁ to thesignal line SL₁ and couples the amplifier SIGAMP₂ to the signal line SL₂at a display timing. The switcher S₁ couples the amplifier SIGAMP₁ tothe signal line SL₂ and couples the amplifier SIGAMP₂ to the signal lineSL₁ at the next display timing.

The amplifier SIGAMP₃ that outputs positive-polarity pixel signals andthe amplifier SIGAMP₄ that outputs negative-polarity pixel signals arepaired with each other. The output terminal of the amplifier SIGAMP₃ andthe output terminal of the amplifier SIGAMP₄ are coupled to a switcherS₂. The switcher S₂ couples the amplifier SIGAMP₃ to the signal line SL₃and couples the amplifier SIGAMP₄ to the signal line SL₄ at a displaytiming. The switcher Sa couples the amplifier SIGAMP₃ to the signal lineSL₄ and couples the amplifier SIGAMP₄ to the signal line SL₃ at the nextdisplay timing.

The amplifier SIGAMP₅ that outputs positive-polarity pixel signals andthe amplifier SIGAMP₆ that outputs negative-polarity pixel signals arepaired with each other. The output terminal of the amplifier SIGAMP₅ andthe output terminal of the amplifier SIGAMP₆ are coupled to a switcherS₃. The switcher S₃ couples the amplifier SIGAMP₅ to the signal line SL₅and couples the amplifier SIGAMP₆ to the signal line SL₆ at a displaytiming. The switcher S₃ couples the amplifier SIGAMP₅ to the signal lineSL₆ and couples the amplifier SIGAMP₆ to the signal line SL₅ at the nextdisplay timing.

The amplifier SIGAMP₇ that outputs positive-polarity pixel signals andthe amplifier SIGAMP₈ that outputs negative-polarity pixel signals arepaired with each other. The output terminal of the amplifier SIGAMP₇ andthe output terminal of the amplifier SIGAMP₈ are coupled to a switcherS₄. The switcher S₄ couples the amplifier SIGAMP₇ to the signal line SL₇and couples the amplifier SIGAMP₈ to the signal line SL₈ at a displaytiming. The switcher S₄ couples the amplifier SIGAMP₇ to the signal lineSL₈ and couples the amplifier SIGAMP₈ to the signal line SL₇ at the nextdisplay timing.

The amplifier SIGAMP₉ that outputs positive-polarity pixel signals andthe amplifier SIGAMP₁₀ that outputs negative-polarity pixel signals arepaired with each other. The output terminal of the amplifier SIGAMP₉ andthe output terminal of the amplifier SIGAMP₁₀ are coupled to a switcherS₅. The switcher S₅ couples the amplifier SIGAMP₉ to the signal line SL₉and couples the amplifier SIGAMP₁₀ to the signal line SL₁₀ at a displaytiming. The switcher S₅ couples the amplifier SIGAMP₉ to the signal lineSL₁₀ and couples the amplifier SIGAMP₁₀ to the signal line SL₉ at thenext display timing.

The amplifier SIGAMP₁₁ that outputs positive-polarity pixel signals andthe amplifier SIGAMP₁₂ that outputs negative-polarity pixel signals arepaired with each other. The output terminal of the amplifier SIGAMP₁₁and the output terminal of the amplifier SIGAMP₁₂ are coupled to aswitcher S₆. The switcher S₆ couples the amplifier SIGAMP₁₁ to thesignal line SL₁₁ and couples the amplifier SIGAMP₁₂ to the signal lineSL₁₂ at a display timing. The switcher S₆ couples the amplifier SIGAMP₁₁to the signal line SL₁₂ and couples the amplifier SIGAMP₁₂ to the signalline SL₁₁ at the next display timing.

A switch SW₁ is disposed between the switcher S₁ and the signal lineSL₁. When a control signal SEL₁ supplied from the COG 11 (refer to FIG.2) is at a high level, the switch SW₁ electrically couples the switcherS₁ to the signal line SL₁. When the control signal SEL₁ is at a lowlevel, the switch SW₁ cuts off electrical coupling between the switcherS₁ and the signal line SL₁. In the image display period, the controlsignal SEL₁ is at a high level. As a result, the switch SW₁ electricallycouples the switcher S₁ to the signal line SL₁, thereby supplying thepixel signal to the signal line SL₁. In an image detection period, thecontrol signal SEL₁ is at a high level. As a result, the switch SW₁electrically couples the switcher S₁ to the signal line SL₁, therebysupplying the pixel signal to the signal line SL₁. In another imagedetection period, the control signal SEL₁ is at a low level. As aresult, the switch SW₁ cuts off electrical coupling between the switcherS₁ and the signal line SL₁, thereby supplying no pixel signal to thesignal line SL₁.

A switch SW₂ is disposed between the switcher S₁ and the signal lineSL₂. When a control signal SEL₂ supplied from the COG 11 (refer to FIG.2) is at a high level, the switch SW₂ electrically couples the switcherS₁ to the signal line SL₂. When the control signal SEL₂ is at a lowlevel, the switch SW₂ cuts off electrical coupling between the switcherS₁ and the signal line SL₂. In the image display period, the controlsignal SEL₂ is at a high level. As a result, the switch SW₂ electricallycouples the switcher S₁ to the signal line SL₂, thereby supplying thepixel signal to the signal line SL₂. In an image detection period, thecontrol signal SEL₂ is at a low level. As a result, the switch SW₂ cutsoff electrical coupling between the switcher S₁ and the signal line SL₂,thereby supplying no pixel signal to the signal line SL₂. In anotherimage detection period, the control signal SEL₂ is at a high level. As aresult, the switch SW₂ electrically couples the switcher S₁ to thesignal line SL₂, thereby supplying the pixel signal to the signal lineSL₂.

A switch SW₃ is disposed between the switcher S₂ and the signal lineSL₃. When a control signal SEL₁ supplied from the COG 11 (refer to FIG.2) is at a high level, the switch SW₃ electrically couples the switcherS₂ to the signal line SL₃. When the control signal SEL₁ is at a lowlevel, the switch SW₃ cuts off electrical coupling between the switcherS₂ and the signal line SL₃. In the image display period, the controlsignal SEL₁ is at a high level. As a result, the switch SW₃ electricallycouples the switcher S₂ to the signal line SL₃, thereby supplying thepixel signal to the signal line SL₃. In an image detection period, thecontrol signal SEL₁ is at a high level. As a result, the switch SW₃electrically couples the switcher S₂ to the signal line SL₃, therebysupplying the pixel signal to the signal line SL₃. In another imagedetection period, the control signal SEL₁ is at a low level. As aresult, the switch SW₃ cuts off electrical coupling between the switcherS₂ and the signal line SL₃, thereby supplying no pixel signal to thesignal line SL₃.

A switch SW₄ is disposed between the switcher S₂ and the signal lineSL₄. When a control signal SEL₂ supplied from the COG 11 (refer to FIG.2) is at a high level, the switch SW₄ electrically couples the switcherS₂ to the signal line SL₄. When the control signal SEL₂ is at a lowlevel, the switch SW₄ cuts off electrical coupling between the switcherS₂ and the signal line SL₄. In the image display period, the controlsignal SEL₂ is at a high level. As a result, the switch SW₄ electricallycouples the switcher S₂ to the signal line SL₄, thereby supplying thepixel signal to the signal line SL₄. In an image detection period, thecontrol signal SEL₂ is at a low level. As a result, the switch SW₄ cutsoff electrical coupling between the switcher S₂ and the signal line SL₄,thereby supplying no pixel signal to the signal line SL₄. In anotherimage detection period, the control signal SEL₂ is at a high level. As aresult, the switch SW₄ electrically couples the switcher S₂ to thesignal line SL₄, thereby supplying the pixel signal to the signal lineSL₄.

A switch SW₅ is disposed between the switcher S₃ and the signal lineSL₅. When a control signal SEL₁ supplied from the COG 11 (refer to FIG.2) is at a high level, the switch SW₅ electrically couples the switcherS₃ to the signal line SL₅. When the control signal SEL₁ is at a lowlevel, the switch SW₅ cuts off electrical coupling between the switcherS₃ and the signal line SL₅. In the image display period, the controlsignal SEL₁ is at a high level. As a result, the switch SW₅ electricallycouples the switcher S₃ to the signal line SL₅, thereby supplying thepixel signal to the signal line SL₅. In an image detection period, thecontrol signal SEL₁ is at a high level. As a result, the switch SW₅electrically couples the switcher S₃ to the signal line SL₅, therebysupplying the pixel signal to the signal line SL₅. In another imagedetection period, the control signal SEL₁ is at a low level. As aresult, the switch SW₅ cuts off electrical coupling between the switcherS₃ and the signal line SL₅, thereby supplying no pixel signal to thesignal line SL₅.

A switch SW₆ is disposed between the switcher S₃ and the signal lineSL₆. When a control signal SEL₂ supplied from the COG 11 (refer to FIG.2) is at a high level, the switch SW₆ electrically couples the switcherS₃ to the signal line SL₆. When the control signal SEL₂ is at a lowlevel, the switch SW₆ cuts off electrical coupling between the switcherS₃ and the signal line SL₆. In the image display period, the controlsignal SEL₂ is at a high level. As a result, the switch SW₆ electricallycouples the switcher S₃ to the signal line SL₆, thereby supplying thepixel signal to the signal line SL₆. In an image detection period, thecontrol signal SEL₂ is at a low level. As a result, the switch SW₆ cutsoff electrical coupling between the switcher S₃ and the signal line SL₆,thereby supplying no pixel signal to the signal line SL₆. In anotherimage detection period, the control signal SEL₂ is at a high level. As aresult, the switch SW₆ electrically couples the switcher S₃ to thesignal line SL₆, thereby supplying the pixel signal to the signal lineSL₆.

A switch SW₇ is disposed between the switcher S₄ and the signal lineSL₇. When a control signal SEL₁ supplied from the COG 11 (refer to FIG.2) is at a high level, the switch SW₇ electrically couples the switcherS₄ to the signal line SL₇. When the control signal SEL₁ is at a lowlevel, the switch SW₇ cuts off electrical coupling between the switcherS₄ and the signal line SL₇. In the image display period, the controlsignal SEL₁ is at a high level. As a result, the switch SW₇ electricallycouples the switcher S₄ to the signal line SL₇, thereby supplying thepixel signal to the signal line SL₇. In an image detection period, thecontrol signal SEL₁ is at a high level. As a result, the switch SW₇electrically couples the switcher S₄ to the signal line SL₇, therebysupplying the pixel signal to the signal line SL₇. In another imagedetection period, the control signal SEL₁ is at a low level. As aresult, the switch SW₇ cuts off electrical coupling between the switcherS₄ and the signal line SL₇, thereby supplying no pixel signal to thesignal line SL₇.

A switch SW₈ is disposed between the switcher S₄ and the signal lineSL₈. When a control signal SEL₂ supplied from the COG 11 (refer to FIG.2) is at a high level, the switch SW₈ electrically couples the switcherS₄ to the signal line SL₈. When the control signal SEL₂ is at a lowlevel, the switch SW₈ cuts off electrical coupling between the switcherS₄ and the signal line SL₈. In the image display period, the controlsignal SEL₂ is at a high level. As a result, the switch SW₈ electricallycouples the switcher S₄ to the signal line SL₈, thereby supplying thepixel signal to the signal line SL₈. In an image detection period, thecontrol signal SEL₂ is at a low level. As a result, the switch SW₈ cutsoff electrical coupling between the switcher S₄ and the signal line SL₈,thereby supplying no pixel signal to the signal line SL₈. In anotherimage detection period, the control signal SEL₂ is at a high level. As aresult, the switch SW₈ electrically couples the switcher S₄ to thesignal line SL₈, thereby supplying the pixel signal to the signal lineSL₈.

A switch SW₉ is disposed between the switcher S₅ and the signal lineSL₉. When a control signal SEL₁ supplied from the COG 11 (refer to FIG.2) is at a high level, the switch SW₉ electrically couples the switcherS₅ to the signal line SL₉. When the control signal SEL₁ is at a lowlevel, the switch SW₉ cuts off electrical coupling between the switcherS₅ and the signal line SL₉. In the image display period, the controlsignal SEL₁ is at a high level. As a result, the switch SW₉ electricallycouples the switcher S₅ to the signal line SL₉, thereby supplying thepixel signal to the signal line SL₉. In an image detection period, thecontrol signal SEL₁ is at a high level. As a result, the switch SW₉electrically couples the switcher S₅ to the signal line SL₉, therebysupplying the pixel signal to the signal line SL₉. In another imagedetection period, the control signal SEL₁ is at a low level. As aresult, the switch SW₉ cuts off electrical coupling between the switcherS₅ and the signal line SL₉, thereby supplying no pixel signal to thesignal line SL₉.

A switch SW₁₀ is disposed between the switcher S₅ and the signal lineSL₁₀. When a control signal SEL₂ supplied from the COG 11 (refer to FIG.2) is at a high level, the switch SW₁₀ electrically couples the switcherS₅ to the signal line SL₁₀. When the control signal SEL₂ is at a lowlevel, the switch SW₁₀ cuts off electrical coupling between the switcherS₅ and the signal line SL₁₀. In the image display period, the controlsignal SEL₂ is at a high level. As a result, the switch SW₁₀electrically couples the switcher S₅ to the signal line SL₁₀, therebysupplying the pixel signal to the signal line SL₁₀. In an imagedetection period, the control signal SEL₂ is at a low level. As aresult, the switch SW₁₀ cuts off electrical coupling between theswitcher S₅ and the signal line SL₁₀, thereby supplying no pixel signalto the signal line SL₁₀. In another image detection period, the controlsignal SEL₂ is at a high level. As a result, the switch SW₁₀electrically couples the switcher S₅ to the signal line SL₁₀, therebysupplying the pixel signal to the signal line SL₁₀.

A switch SW₁₁ is disposed between the switcher S₆ and the signal lineSL₁₁. When a control signal SEL₁ supplied from the COG 11 (refer to FIG.2) is at a high level, the switch SW₁₁ electrically couples the switcherS₆ to the signal line SL₁₁. When the control signal SEL₁ is at a lowlevel, the switch SW₁₁ cuts off electrical coupling between the switcherS₆ and the signal line SL₁₁. In the image display period, the controlsignal SEL₁ is at a high level. As a result, the switch SW₁₁electrically couples the switcher S₆ to the signal line SL₁₁, therebysupplying the pixel signal to the signal line SL₁₁. In an imagedetection period, the control signal SEL₁ is at a high level. As aresult, the switch SW₁₁ electrically couples the switcher S₆ to thesignal line SL₁₁, thereby supplying the pixel signal to the signal lineSL₁₁. In another image detection period, the control signal SEL₁ is at alow level. As a result, the switch SW₁₁ cuts off electrical couplingbetween the switcher S₆ and the signal line SL₁₁, thereby supplying nopixel signal to the signal line SL₁₁.

A switch SW₁₂ is disposed between the switcher S₆ and the signal lineSL₁₂. When a control signal SEL₂ supplied from the COG 11 (refer to FIG.2) is at a high level, the switch SW₁₂ electrically couples the switcherS₆ to the signal line SL₁₂. When the control signal SEL₂ is at a lowlevel, the switch SW₁₂ cuts off electrical coupling between the switcherS₆ and the signal line SL₁₂. In the image display period, the controlsignal SEL₂ is at a high level. As a result, the switch SW₁₂electrically couples the switcher S₆ to the signal line SL₁₂, therebysupplying the pixel signal to the signal line SL₁₂. In an imagedetection period, the control signal SEL₂ is at a low level. As aresult, the switch SW₁₂ cuts off electrical coupling between theswitcher S₆ and the signal line SL₁₂, thereby supplying no pixel signalto the signal line SL₁₂. In another image detection period, the controlsignal SEL₂ is at a high level. As a result, the switch SW₁₂electrically couples the switcher S₆ to the signal line SL₁₂, therebysupplying the pixel signal to the signal line SL₁₂.

The drive electrode driver 9 includes an amplifier COMAMP that outputsthe drive signals VCOM to the drive electrodes COML₁ and COML₂. Thedrive signal VCOM is a ground potential GND, for example, but is notlimited thereto. The drive signal VCOM may be a positive-polarityconstant potential or a negative-polarity constant potential.

A switch SW₂₁ is disposed between the amplifier COMAMP and the driveelectrode COML₁. When a control signal SEL₃ supplied from the COG 11(refer to FIG. 2) is at a high level, the switch SW₂₁ electricallycouples the amplifier COMAMP to the drive electrode COML₁. When thecontrol signal SEL₃ is at a low level, the switch SW₂₁ cuts offelectrical coupling between the amplifier COMAMP and the drive electrodeCOML₁. In the image display period, the control signal SEL₃ is at a highlevel. As a result, the switch SW₂₁ electrically couples the amplifierCOMAMP to the drive electrode COML₁, thereby supplying the drive signalVCOM to the drive electrode COML₁. In the image detection period, thecontrol signal SEL₃ is at a low level. As a result, the switch SW₂₁ cutsoff electrical coupling between the amplifier COMAMP and the driveelectrode COML₁, thereby supplying no drive signal VCOM to the driveelectrode COML₁.

A switch SW₂₂ is disposed between the amplifier COMAMP and the driveelectrode COML₂. When a control signal SEL₃ supplied from the COG 11(refer to FIG. 2) is at a high level, the switch SW₂₂ electricallycouples the amplifier COMAMP to the drive electrode COML₂. When thecontrol signal SEL₃ is at a low level, the switch SW₂₂ cuts offelectrical coupling between the amplifier COMAMP and the drive electrodeCOML₂. In the image display period, the control signal SEL₃ is at a highlevel. As a result, the switch SW₂₂ electrically couples the amplifierCOMAMP to the drive electrode COML₂, thereby supplying the drive signalVCOM to the drive electrode COML₂. In the image detection period, thecontrol signal SEL₃ is at a low level. As a result, the switch SW₂₂ cutsoff electrical coupling between the amplifier COMAMP and the driveelectrode COML₂, thereby supplying no drive signal VCOM to the driveelectrode COML₂.

While one of the drive electrodes COML and one of the detection lines RLaccording to the present embodiment are provided for every two columnsof the pixels Pix, the configuration is not limited thereto. The displayapparatus 1 according to the present embodiment employs the columninversion driving method, and two amplifiers SIGAMP are paired with eachother. One pixel Pix includes three (three-color) sub-pixels SPix, andthree signal lines SL are coupled to one pixel Pix. Consequently, one ofthe drive electrodes COML and one of the detection lines RL arepreferably provided for every multiple of six signal lines SL, which isthe least common multiple of 2 and 3. In other words, one of the driveelectrodes COML and one of the detection lines RL are preferablyprovided for every two, four, six, . . . columns of the pixels Pix. In acase where one of the drive electrodes COML and one of the detectionlines RL are provided for every four columns of the pixels Pix, thenumber of pieces of detection pixel data in one line of the detectionimage data is (N/4). In a case where one of the drive electrodes COMLand one of the detection lines RL are provided for every six columns ofthe pixels Pix, the number of pieces of detection pixel data in one lineof the detection image data is (N/6).

1-1. First Exemplary Operation Performed by the Display ApparatusAccording to the First Embodiment

The following describes a first exemplary operation performed by thedisplay apparatus 1 according to the first embodiment. In the firstexemplary operation, the display apparatus 1 divides the pixels of Mrows into L units and performs image display and image detection on aunit-by-unit basis. The signal lines SL and the detection lines RLextend in the column direction intersecting the rows of the pixels. Todetect an image, the display apparatus 1 applies data to the signallines SL on a unit-by-unit basis and detects display data on aunit-by-unit basis with the detection lines RL extending parallel to thesignal lines SL.

FIG. 6 is a diagram of the display area of the display apparatusaccording to the first embodiment.

M horizontal lines in the display area DA are divided into L units fromthe first unit U₁ to the L-th (L is an integer of 2 or larger) unitU_(L). The first unit U₁ to the L-th unit U_(L) each include (M/L)horizontal lines. In a case where the display area DA has 480 horizontallines and is divided into ten units, for example, each of the ten unitsincludes 48 horizontal lines.

FIG. 7 is a diagram of an operating sequence in the first exemplaryoperation performed by the display apparatus according to the firstembodiment. FIG. 7 illustrates an operating sequence of two framesperformed by the display apparatus 1. As illustrated in FIG. 7, thedisplay apparatus 1 sequentially performs control on the L units fromthe first unit U₁ to the L-th unit U_(L). In FIG. 7, the period fromtiming t₀ to timing t₇ corresponds to the first frame, and the periodfrom timing t₇ to timing t₁₄ corresponds to the second frame.

From timing t₀ to timing t₁, the display apparatus 1 performs imagedisplay for the first frame on the (M/L) horizontal lines included inthe first unit U₁. In the image display performed from timing t₀ totiming t₁, the display apparatus 1 applies both the positive- and thenegative-polarity pixel signals to display an image. From timing t₁ totiming t₂, the display apparatus 1 performs positive-polarity imagedetection (detection of the positive-polarity pixel signals) for thefirst frame on the (M/L) horizontal lines included in the first unit U₁.In the image detection performed from timing t₁ to timing t₂, thedisplay apparatus 1 applies only the positive-polarity pixel signals toperform image detection (detection of the positive-polarity pixelsignals).

From timing t₀ to timing t₃, the display apparatus 1 performs imagedisplay for the first frame on the (M/L) horizontal lines included inthe second unit U₂. From timing t₃ to timing t₄, the display apparatus 1performs positive-polarity image detection (detection of thepositive-polarity pixel signals) for the first frame on the (M/L)horizontal lines included in the second unit U₂.

From timing t₄ to timing t₅, similarly to from timing t₀ to timing t₄,the display apparatus 1 performs image display and image detection(detection of the positive-polarity pixel signals). From timing is totiming t₆, the display apparatus 1 performs image display for the firstframe on the (M/L) horizontal lines included in the L-th unit U_(L).From timing t₆ to timing t₇, the display apparatus 1 performspositive-polarity image detection (detection of the positive-polaritypixel signals) for the first frame on the (M/L) horizontal linesincluded in the L-th unit U_(L).

From timing t₇ to timing t₈, the display apparatus 1 performs imagedisplay for the second frame on the (M/L) horizontal lines included inthe first unit U₁. In the image display performed from timing t₇ totiming t₈, the display apparatus 1 applies both the positive- and thenegative-polarity pixel signals to display an image. From timing is totiming t₉, the display apparatus 1 performs negative-polarity imagedetection (detection of the negative-polarity pixel signals) for thesecond frame on the (M/L) horizontal lines included in the first unitU₁. In the image detection performed from timing is to timing t₉, thedisplay apparatus 1 applies only the negative-polarity pixel signals toperform image detection (detection of the negative-polarity pixelsignals).

From timing t₉ to timing t₁₀, the display apparatus 1 performs imagedisplay for the second frame on the (M/L) horizontal lines included inthe second unit U₂. From timing t₁₀ to timing t₁₁, the display apparatus1 performs negative-polarity image detection (detection of thenegative-polarity pixel signals) for the second frame on the (M/L)horizontal lines included in the second unit U₂.

From timing t₁₁ to timing t₁₂, similarly to from timing t₉ to timingt₁₁, the display apparatus 1 performs image display and image detection(detection of the negative-polarity pixel signals). From timing t₁₂ totiming t₁₃, the display apparatus 1 performs image display for thesecond frame on the (M/L) horizontal lines included in the L-th unitU_(L). From timing t₁₃ to timing t₁₄, the display apparatus 1 performsnegative-polarity image detection (detection of the negative-polaritypixel signals) for the second frame on the (M/L) horizontal linesincluded in the L-th unit U_(L).

FIG. 8 is a diagram of an operating timing in the first exemplaryoperation performed by the display apparatus according to the firstembodiment.

A timing signal TSVD for detection control output from the COG 11 to theCOF 12 is the same as the vertical synchronization signal for displaycontrol for displaying an image on the display device DSP by the COG 11,for example. The period from timing to of the first rising edge of thetiming signal TSVD to timing t₂₄ of the second rising edge of the timingsignal TSVD corresponds to the period of image display and imagedetection of the first frame. The period after timing t₂₄ of the secondrising edge of the timing signal TSVD corresponds to the period of imagedisplay and image detection of the second frame.

A timing signal TSHD for detection control output from the COG 11 to theCOF 12 indicates the image display period and the image detectionperiod. In the image display period, the COG 11 outputs the timingsignal TSHD at a low level to the COF 12. In the image detection period,the COG 11 outputs the timing signal TSHD at a high level to the COF 12.

A timing signal HSYNC for detection control output from the COG 11 tothe COF 12 has the same frequency as that of the horizontalsynchronization signal for display control for displaying an image onthe display device DSP by the COG 11, for example. The COF 12 is acircuit that performs not display control but detection control. In theimage display period, that is, the period when the timing signal TSHD isat a low level, the COG 11 need not change the timing signal HSYNC. Bycontrast, in the image detection period, that is, the period when thetiming signal TSHD is at a high level, the COG 11 changes the timingsignal HSYNC at the same frequency as that of the horizontalsynchronization signal for display control.

From timing t₂₁ to timing t₂₂, the host HST outputs image data for (M/L)horizontal lines of the first unit U₁ of the first frame to the COG 11.The COG 11 temporarily stores the image data for (M/L) horizontal linessupplied from the host HST in the buffer 11 a (refer to FIG. 2). Thebuffer 11 a simply needs to have storage capacity large enough to storetherein image data for (M/L) horizontal lines.

The period from timing t₂₁ to timing t₂₂ corresponds to the imagedisplay period for the first unit U₁ of the first frame. From timing t₂₁to timing t₂₂, the COG 11 outputs the control signals SEL₁ and SEL₂(refer to FIG. 5) at a high level to the horizontal driver 8. As aresult, the switches SW₁ to SW₁₂ are turned on.

The COG 11 causes the horizontal driver 8 to output the pixel signalsbased on the image data for (M/L) horizontal lines of the first unit U₁of the first frame stored in the buffer 11 a. The horizontal driver 8outputs positive-polarity pixel signals SIG_(PLUS) to one group of twogroups (a group of the odd-numbered signal lines SL and a group of theeven-numbered signal lines SL) of the N signal lines SL. The horizontaldriver 8 outputs negative-polarity pixel signals SIG_(MINUS) to theother group of the two groups of the N signal lines SL.

The horizontal driver 8, for example, outputs the positive-polaritypixel signals SIG_(PLUS) to the group of the odd-numbered signal linesSL (refer to the signal lines SL₁, SL₃, SL₅, . . . in FIG. 5) out of theN signal lines SL. The horizontal driver 8 outputs the negative-polaritypixel signals SIG_(MINUS) to the group of the even-numbered signal linesSL (refer to the signal lines SL₂, SL₄, SL₆, . . . in FIG. 5) out of theN signal lines SL.

From timing t₂₁ to timing t₂₂, the COG 11 outputs the control signalSEL₃ (refer to FIG. 5) at a high level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned on. The driveelectrode driver 9 outputs the drive signals VCOM to all the driveelectrodes COML. Consequently, an electric field is formed between thepixel electrodes PE (refer to FIG. 4) and the drive electrodes COML,thereby displaying an image.

The period from timing t₂₂ to timing t₂₃ corresponds to thepositive-polarity image detection period for the first unit U₁ of thefirst frame. From timing t₂₂ to timing t₂₃, the COG 11 outputs thecontrol signal SEL₁ at a high level and the control signal SEL₂ at a lowlevel (refer to FIG. 5) to the horizontal driver 8. As a result, theodd-numbered switches SW₁, SW₃, SW₅, . . . are turned on, and theeven-numbered switches SW₂, SW₄, SW₆, . . . are turned off.

The COG 11 causes the horizontal driver 8 to output the pixel signalsbased on the image data for (M/L) horizontal lines of the first unit U₁of the first frame stored in the buffer 11 a. In other words, fromtiming t₂₂ to timing t₂₃, the horizontal driver 8 outputs again the samesignals as the positive-polarity pixel signals SIG_(PLUS) output fromtiming t₂₁ to timing t₂₂. The horizontal driver 8 outputs thepositive-polarity pixel signals SIG_(PLUS) to the group of theodd-numbered signal lines SL (refer to the signal lines SL₁, SL₃, SL₅, .. . in FIG. 5) out of the N signal lines SL.

From timing t₂₂ to timing t₂₃, the COG 11 outputs the control signalSEL₃ (refer to FIG. 5) at a low level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned off. Consequently,all the drive electrodes COML are brought into a floating state. The COG11 may bring at least only the drive electrode COML at the positioncorresponding to the detection line RL that is actually performingdetection into a floating state.

Referring back to FIG. 5, when the drive electrode COML₁ is in afloating state, the electric potential of the drive electrode COML₁changes due to the pixel signals SIG_(PLUS) supplied to the signal linesSL₁, SL₃, and SL₅. Because the signal lines SL₁, SL₃, and SL₅ arecapacitively coupled to the detection line RL₁, a detection signal isgenerated in the detection line RL₁ due to the pixel signals SIG_(PLUS)supplied to the signal lines SL₁, SL₃, and SL₅. The COF 12 reads thedetection signal generated in the detection line RL₁ at a timing basedon the timing signal HSYNC. The COF 12 performs sampling and A/D(analog/digital) conversion on the detection signal, thereby obtainingpositive-polarity detection pixel data.

Similarly, the COG 11 and the COF 12 perform image display andpositive-polarity image detection for the first frame on the second unitU₂ to the L-th unit U_(L).

Referring back to FIG. 8, at timing t₂₅, the host HST outputs image datafor (M/L) horizontal lines of the first unit U₁ of the second frame tothe COG 11. The COG 11 temporarily stores the image data for (M/L)horizontal lines supplied from the host HST in the buffer 11 a (refer toFIG. 2).

The period from timing t₂₅ to timing t₂₆ corresponds to the imagedisplay period for the first unit U₁ of the second frame. From timingt₂₅ to timing t₂₆, the COG 11 outputs the control signals SEL₁ and SEL₂(refer to FIG. 5) at a high level to the horizontal driver 8. Becausethe period from timing t₂₅ to timing t₂₆ corresponds to the imagedisplay period, the switches SW₁ to SW₁₂ are turned on, and thedetection lines RL do not relate to the operation.

The COG 11 causes the horizontal driver 8 to output the pixel signalsbased on the image data for (M/L) horizontal lines of the first unit U₁of the second frame stored in the buffer 11 a. The horizontal driver 8outputs positive-polarity pixel signals SIG_(PLUS) to one group of thetwo groups (the group of the odd-numbered signal lines SL and the groupof the even-numbered signal lines SL) of the N signal lines SL. Thehorizontal driver 8 outputs negative-polarity pixel signals SIG_(MINUS)to the other group of the two groups of the N signal lines SL.

The horizontal driver 8, for example, outputs the positive-polaritypixel signals SIG_(PLUS) to the group of the odd-numbered signal linesSL (refer to the signal lines SL₁, SL₃, SL₅, . . . in FIG. 5) out of theN signal lines SL. The horizontal driver 8 outputs the negative-polaritypixel signals SIG_(MINUS) to the group of the even-numbered signal linesSL (refer to the signal lines SL₂, SL₄, SL₆, . . . in FIG. 5) out of theN signal lines SL.

From timing t₂₅ to timing t₂₆, the COG 11 outputs the control signalSEL₃ (refer to FIG. 5) at a high level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned on. The driveelectrode driver 9 outputs the drive signals VCOM to all the driveelectrodes COML. Consequently, an electric field is formed between thepixel electrodes PE (refer to FIG. 4) and the drive electrodes COML,thereby displaying an image.

The period from timing t₂₆ to timing t₂₇ corresponds to thenegative-polarity image detection period for the first unit U₁ of thesecond frame. From timing t₂₆ to timing t₂₇, the COG 11 outputs thecontrol signal SEL₁ at a low level and the control signal SEL₂ at a highlevel (refer to FIG. 5) to the horizontal driver 8. As a result, theodd-numbered switches SW₁, SW₃, SW₅, . . . are turned off, and theeven-numbered switches SW₂, SW₄, SW₆, . . . are turned on.

The COG 11 causes the horizontal driver 8 to output the pixel signalsbased on the image data for (M/L) horizontal lines of the first unit U₁of the second frame stored in the buffer 11 a. In other words, fromtiming t₂₆ to timing t₂₇, the horizontal driver 8 outputs again the samesignals as the negative-polarity pixel signals SIG_(MINUS) output fromtiming t₂₅ to timing t₂₆. The horizontal driver 8 outputs thenegative-polarity pixel signals SIG_(MINUS) to the group of theeven-numbered signal lines SL (refer to the signal lines SL₂, SL₄, SL₆,. . . in FIG. 5) out of the N signal lines SL.

From timing t₂₆ to timing t₂₇, the COG 11 outputs the control signalSEL₃ (refer to FIG. 5) at a low level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned off. Consequently,all the drive electrodes COML are brought into a floating state.

Referring back to FIG. 5, when the drive electrode COML₁ is in afloating state, the electric potential of the drive electrode COML₁changes due to the pixel signals SIG_(MINUS) supplied to the signallines SL₂, SL₄, and SL₆. Because the signal lines SL₂, SL₄, and SL₆ arecapacitively coupled to the detection line RL₁, a detection signal isgenerated in the detection line RL₁ due to the pixel signals SIG_(MINUS)supplied to the signal lines SL₂, SL₄, and SL₆. The COF 12 reads thedetection signal generated in the detection line RL₁ at a timing basedon the timing signal HSYNC. The COF 12 performs sampling and A/Dconversion on the detection signal, thereby obtaining negative-polaritydetection pixel data. The COF 12 may read the peak voltage of thedetection signal, thereby obtaining the negative-polarity detectionpixel data.

Similarly, the COG 11 and the COF 12 perform image display andnegative-polarity image detection for the second frame on the secondunit U₂ to the L-th unit U_(L).

FIG. 9 is another diagram of the operating timing in the first exemplaryoperation performed by the display apparatus according to the firstembodiment. FIG. 9 illustrates the period from timing t₂₂ to timing t₂₃in FIG. 8, that is, the positive-polarity image detection period for thefirst unit U₁ of the first frame in greater detail.

The positive-polarity image detection period for the first unit U₁ ofthe first frame starts at timing t₃₀ corresponding to the rising edge ofthe timing signal TSHD. The period from timing t₃₀ corresponding to thefirst rising edge of the timing signal HSYNC to timing t₃₂ correspondingto the second rising edge of the timing signal HSYNC corresponds to thefirst horizontal period (1H).

The period from timing t₃₀ to timing t₃₁, which is a predetermined timeafter timing t₃₀, corresponds to a precharge period for the signal linesSL.

From timing t₃₀ to timing t₃₁, the amplifier SIGAMP₁ (refer to FIG. 5)of the horizontal driver 8 outputs the ground potential GND to thesignal line SL₁, thereby precharging the signal line SL₁ with the groundpotential GND. From timing t₃₀ to timing t₃₁, the amplifier SIGAMP₃(refer to FIG. 5) of the horizontal driver 8 outputs the groundpotential GND to the signal line SL₃, thereby precharging the signalline SL₃ with the ground potential GND. From timing t₃₀ to timing t₃₁,the amplifier SIGAMP₅ (refer to FIG. 5) of the horizontal driver 8outputs the ground potential GND to the signal line SL₅, therebyprecharging the signal line SL₅ with the ground potential GND.

At timing t₃₁, the amplifier SIGAMP₁ of the horizontal driver 8 outputsa positive-polarity pixel signal SIG_(PLUS_1) of red (R) to the signalline SL₁. At timing t₃₁, the amplifier SIGAMP₃ of the horizontal driver8 outputs a positive-polarity pixel signal SIG_(PLUS_2) of blue (B) tothe signal line SL₃. At timing t₃₁, the amplifier SIGAMP₅ of thehorizontal driver 8 outputs a positive-polarity pixel signalSIG_(PLUS_3) of green (G) to the signal line SL₅.

When the pixel signals SIG_(PLUS_1), SIG_(PLUS_2), and SIG_(PLUS_3) areoutput to the signal lines SL₁, SL₃, and SL₅, respectively, a detectionsignal SIG_(RL) is generated in the detection line RL₁ due to the pixelsignals SIG_(PLUS_1), SIG_(PLUS_2), and SIG_(PLUS_3). The detectionsignal SIG_(RL), is a differential signal of a voltage V₄. The COF 12detects the differential waveform to calculate the voltage V₄. When V₁is the voltage of the pixel signal SIG_(PLUS_1), V₂ is the voltage ofthe pixel signal SIG_(PLUS_2), and V₃ is the voltage of the pixel signalSIG_(PLUS_3), the voltage V₄ indicated by the dotted line is expressedby (V₁+V₂+V₃)/3, for example. The detection signal SIG_(RL) indicated bythe solid line is detected in a case where the detection circuit 12described in FIG. 17, for example, is coupled to the detection line RL₁and RL₂.

At a timing when the detection signal SIG_(RL), becomes stable, that is,when a predetermined time has passed since timing t₃₀ corresponding tothe rising edge of the timing signal HSYNC, the COF 12 reads thedetection signal SIG_(RL). The COF 12 performs sampling and A/Dconversion on the detection signal, thereby obtaining thepositive-polarity detection pixel data. The COF 12 may read the peakvoltage of the detection signal SIG_(RL), indicated by the solid line,thereby obtaining the positive-polarity detection pixel data.

From timing t₃₂ to timing t₃₃, which is a predetermined time aftertiming t₃₂, the amplifier SIGAMP₁ of the horizontal driver 8 outputs theground potential GND to the signal line SL₁, thereby precharging thesignal line SL₁ with the ground potential GND. From timing t₃₂ to timingt₃₃, which is a predetermined time after timing t₃₂, the amplifierSIGAMP₃ of the horizontal driver 8 outputs the ground potential GND tothe signal line SL₃, thereby precharging the signal line SL₃ with theground potential GND. From timing t₃₂ to timing t₃₃, which is apredetermined time after timing t₃₂, the amplifier SIGAMP₅ of thehorizontal driver 8 outputs the ground potential GND to the signal lineSL₅, thereby precharging the signal line SL₅ with the ground potentialGND.

Similarly, the COF 12 performs positive-polarity image detection on thesecond and subsequent lines.

As described above, the number of pieces of detection pixel data in oneline of the detection image data is (N/2). As illustrated in FIGS. 8 and9, the display apparatus 1 performs image detection on a line-by-linebasis. Consequently, the detection image data includes M×(N/2) pieces ofpixel data. The display apparatus 1 may integrate (M/L) pieces ofdetection pixel data included in one column of one unit U into one pieceof data. The display apparatus 1, for example, may perform an arithmeticmean or geometric mean calculation on (M/L) pieces of detection pixeldata included in one column of one unit U, thereby obtaining one pieceof detection pixel data. In this case, the detection image data includesLx(N/2) pieces of pixel data.

FIG. 10 is a flowchart of an operation in the first exemplary operationperformed by the display apparatus according to the first embodiment.The display apparatus 1 performs the operation illustrated in FIG. 10 ona frame-by-frame basis.

At Step S100, the host HST initializes a variable i to 1. The variable iindicates the number of the unit to be subjected to image display andimage detection.

At Step S102, the host HST transmits image data for (M/L) horizontallines of the i-th unit U, to the COG 11.

At Step S104, the COG 11 displays an image of the i-th unit U.

At Step S106, the COF 12 detects a positive- or negative-polarity imageof the i-th unit

At Step S108, the host HST reads positive- or negative-polaritydetection image data of the i-th unit U_(i) from the COF 12.

At Step S110, the host HST determines whether the variable i is equal toL, that is, whether image display and image detection for the L-th unitU_(L) are finished. If the host HST determines that the variable i isnot equal to L (No at Step S110), the host HST performs the processingat Step S112. If the host HST determines that the variable i is equal toL (Yes at Step S110), the host HST performs the processing at Step S114.

If the host HST determines that the variable i is not equal to L (No atStep S110), the host HST increments the variable i at Step S112 andperforms the processing at Step S102 again.

If the host HST determines that the variable i is equal to L (Yes atStep S110), the host HST calculates reference image data based on theimage data used in image display at Step S114. If a positive-polarityimage of the i-th unit is detected from Step S102 to Step S108, the hostHST removes pixel data output with the negative polarity from the imagedata and thus calculates the reference image data including only pixeldata output with the positive polarity in the image data. If anegative-polarity image of the i-th unit is detected from Step S102 toStep S108, the host HST removes pixel data output with the positivepolarity from the image data and calculates the reference image dataincluding only pixel data output with the negative polarity in the imagedata.

The image data includes M×N pieces of pixel data because the displayarea DA includes M×N pixels Pix. By contrast, the detection image dataincludes M×(N/2) or Lx(N/2) pieces of detection pixel data as describedabove. The host HST performs resizing operation of reducing the numberof pixels on the image data, thereby determining the reference imagedata.

At Step S116, the host HST compares the reference image data with thedetection image data. The host HST compares the reference image datawith the detection image data on a pixel-by-pixel basis. In other words,the host HST compares the pixel data of the m-th row (m is an integersatisfying 1≤m≤M or 1≤m≤L) and the n-th column (n is an integersatisfying 1≤n≤(N/2)) in the reference image data with the detectionpixel data of the m-th row and the n-th column in the detection imagedata. The host HST may compare the reference image data with thedetection image data allowing a predetermined latitude in the pieces ofpixel data in the reference image data or those in the detection imagedata while considering detection error in the detection image data.

When comparing the reference image data with the detection image data,the host HST may perform correction on the reference image data or thedetection image data.

FIG. 11 is a graph of an example of the relation between the detectionsignal and the detection image data. The relation between the gradationof image data and the gradation of an image actually displayed on thedisplay device DSP is represented not by a linear shape like a line 51but by a nonlinear shape like a line 52, for example. Consequently, thepixel signals are subjected to gamma correction as indicated by a line53. The detection lines RL generate the detection signals due to thepixel signals. As a result, the detection signals are affected by gammacorrection. To address this, the host HST may perform reverse correctionof the gamma correction on the detection image data and then compare thereference image data with the detection image data. In other words, thehost HST may define the detection image data not as an intersection B ofa detection signal A and the line 51 but as an intersection C of thedetection signal A and the line 53. Alternatively, the host HST mayperform gamma correction on the reference image data and then comparethe reference image data with the detection image data.

Referring back to FIG. 10, at Step S118, the host HST determines whetherthe matching ratio between the reference image data and the detectionimage data is equal to or higher than a predetermined threshold. Thehost HST divides the number of pieces of detection pixel data matchingthe reference pixel data by the number of all the pieces of detectionpixel data in the detection image data, thereby calculating the matchingratio.

If the host HST determines that the matching ratio is equal to or higherthan the predetermined threshold (Yes at Step S118), the host HSTperforms the processing at Step S120. If the host HST determines thatthe matching ratio is not equal to or higher than the predeterminedthreshold (No at Step S118), the host HST performs the processing atStep S122.

If the host HST determines that the matching ratio is equal to or higherthan the predetermined threshold (Yes at Step S118), the host HSTdetermines that the image is normally displayed at Step S120 and thenfinishes the processing.

If the host HST determines that the matching ratio is not equal to orhigher than the predetermined threshold (No at Step S118), the host HSTdetermines that the image is not normally displayed at Step S122. Thehost HST displays an onboard warning lamp or restarts or stops thedisplay apparatus 1 at Step S124 and then finishes the processing.

1-2. Second Exemplary Operation Performed by the Display ApparatusAccording to the First Embodiment

The following describes a second exemplary operation performed by thedisplay apparatus 1 according to the first embodiment. In the secondexemplary operation, the display apparatus 1 performs image display andimage detection row by row.

FIG. 12 is a diagram of an operating timing in the second exemplaryoperation performed by the display apparatus according to the firstembodiment.

The period from timing too of the first rising edge of the timing signalTSVD to timing t₄₈ of the second rising edge of the timing signal TSVDcorresponds to the period of image display and image detection of thefirst frame. The period after timing t₄₈ of the second rising edge ofthe timing signal TSVD corresponds to the period of image display andimage detection of the second frame.

A timing signal HSYNC for detection control output from the COG 11 tothe COF 12 has the same frequency as that of the horizontalsynchronization signal for display control for displaying an image onthe display device DSP by the COG 11, for example.

During the entire period, the COG 11 outputs the control signals SEL₁and SEL₂ (refer to FIG. 5) at a high level to the horizontal driver 8.As a result, the switches SW₁ to SW₁₂ are turned on.

The period from timing t₄₁ to timing t₄₄ corresponds to apositive-polarity image detection and display writing (image display)period for the first horizontal line of the first frame.

At timing t₄₁, the host HST outputs image data for the first horizontalline of the first frame to the COG 11. The COG 11 temporarily stores theimage data for the first horizontal line of the first frame suppliedfrom the host HST in the buffer 11 a (refer to FIG. 2). The buffer 11 asimply needs to have storage capacity large enough to store thereinimage data of one horizontal line.

The period from timing t₄₁ to timing t₄₂, which is a predetermined timeafter timing t₄₁, corresponds to a precharge period for the signal linesSL.

From timing t₄₁ to timing t₄₂, the horizontal driver 8 outputs theground potential GND to all the signal lines SL, thereby precharging allthe signal lines SL with the ground potential GND.

The period from timing t₄₂ to timing t₄₃ corresponds to thepositive-polarity image detection period for the first horizontal lineof the first frame.

At timing t₄₂, the COG 11 causes the horizontal driver 8 to output thepositive-polarity pixel signals for the first horizontal line of thefirst frame based on the image data for the first horizontal line of thefirst frame stored in the buffer 11 a. The horizontal driver 8 outputsthe positive-polarity pixel signals SIG_(PLUS) for the first horizontalline of the first frame to one group of the two groups (the group of theodd-numbered signal lines SL and the group of the even-numbered signallines SL) of the N signal lines SL. The horizontal driver 8 maintainsthe electric potential (ground potential GND) of the other group of thetwo groups of the N signal lines SL.

The horizontal driver 8, for example, outputs the positive-polaritypixel signals SIG_(PLUS) for the first horizontal line of the firstframe to the group of the odd-numbered signal lines SL (refer to thesignal lines SL₁, SL₃, SL₅, . . . in FIG. 5) out of the N signal linesSL. The horizontal driver 8 maintains the electric potential (groundpotential GND) of the group of the even-numbered signal lines SL (referto the signal lines SL₂, SL₄, SL₆, . . . in FIG. 5) out of the N signallines SL.

From timing t₄₁ to timing t₄₃, the COG 11 outputs the control signalSEL₃ (refer to FIG. 5) at a low level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned off. Consequently,all the drive electrodes COML are brought into a floating state.

Referring back to FIG. 5, when the drive electrode COML₁ is in afloating state, the electric potential of the drive electrode COML₁changes due to the pixel signals SIG_(PLUS) supplied to the signal linesSL₁, SL₃, and SL₅. Because the signal lines SL₁, SL₃, and SL₅ arecapacitively coupled to the detection line RL₁, the detection signalSIG_(RL) is generated in the detection line RL₁ due to the pixel signalsSIG_(PLUS) supplied to the signal lines SL₁, SL₃, and SL₅. The COF 12reads the detection signal SIG_(RL), at a timing based on the timingsignal HSYNC, for example, at timing t₄₂. The COF 12 performs samplingand A/D conversion on the detection signal, thereby obtaining thepositive-polarity detection pixel data. The detection signal SIG_(RL),indicated by the slid line is a spike signal that is detected in a case,for example, where the detection circuit 12 described in FIG. 17 iscoupled to the detection line RL₁ and RL₂. The COF 12 may read the peakvoltage of the detection signal SIG_(RL), thereby obtaining thepositive-polarity detection pixel data.

The period from timing t₄₃ to timing t₄₄ corresponds to the displaywriting (image display) period for the first horizontal line of thefirst frame.

At timing t₄₃, the COG 11 causes the horizontal driver 8 to output thepixel signals based on the image data for the first horizontal line ofthe first frame stored in the buffer 11 a. The horizontal driver 8maintains the electric potential (positive-polarity pixel signalsSIG_(PLUS) for the first horizontal line of the first frame) of onegroup of the two groups (the group of the odd-numbered signal lines SLand the group of the even-numbered signal lines SL) of the N signallines SL. The horizontal driver 8 outputs the negative-polarity pixelsignals SIG_(MINUS) for the first horizontal line of the first frame tothe other group of the two groups of the N signal lines SL.

The horizontal driver 8, for example, maintains the electric potential(positive-polarity pixel signals SIG_(PLUS) for the first horizontalline of the first frame) of the group of the odd-numbered signal linesSL (refer to the signal lines SL₁, SL₃, SL₅, . . . in FIG. 5) out of theN signal lines SL. The horizontal driver 8 outputs the negative-polaritypixel signals SIG_(MINUS) for the first horizontal line of the firstframe to the group of the even-numbered signal lines SL (refer to thesignal lines SL₂, SL₄, SL₆, . . . in FIG. 5) out of the N signal linesSL.

From timing t₄₃ to timing t₄₄, the COG 11 outputs the control signalSEL₃ (refer to FIG. 5) at a high level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned on. The driveelectrode driver 9 outputs the drive signals VCOM to all the driveelectrodes COML. Consequently, an electric field is formed between thepixel electrodes PE (refer to FIG. 4) and the drive electrodes COML,thereby displaying an image.

The period from timing t₄₄ to timing t₄₇ corresponds to apositive-polarity image detection and display writing (image display)period for the second horizontal line of the first frame.

At timing t₄₄, the host HST outputs image data for the second horizontalline of the first frame to the COG 11. The COG 11 temporarily stores theimage data for the second horizontal line of the first frame suppliedfrom the host HST in the buffer 11 a (refer to FIG. 2).

The period from timing t₄₄ to timing t₄₅, which is a predetermined timeafter timing t₄₄, corresponds to a precharge period for the signal linesSL.

From timing t₄₄ to timing t₄₅, the horizontal driver 8 outputs theground potential GND to one group of the two groups (the group of theodd-numbered signal lines SL and the group of the even-numbered signallines SL) of the N signal lines SL. The horizontal driver 8 thusprecharges the group of the odd-numbered or the even-numbered signallines SL in the N signal lines SL with the ground potential GND. Fromtiming t₄₄ to timing t₄₅, the horizontal driver 8 maintains the electricpotential (negative-polarity pixel signals SIG_(MINUS) for the firsthorizontal line of the first frame) of the other group of the two groupsof the N signal lines SL.

The horizontal driver 8, for example, outputs the ground potential GNDto the group of the odd-numbered signal lines SL (refer to the signallines SL₁, SL₃, SL₅, . . . in FIG. 5) out of the N signal lines SL. Thehorizontal driver 8 maintains the electric potential (negative-polaritypixel signals SIG_(MINUS) for the first horizontal line of the firstframe) of the group of the even-numbered signal lines SL (refer to thesignal lines SL₂, SL₄, SL₆, . . . in FIG. 5) out of the N signal linesSL.

The period from timing t₄₅ to timing t₄₆ corresponds to thepositive-polarity image detection period for the second horizontal lineof the first frame.

At timing t₄₅, the COG 11 causes the horizontal driver 8 to output thepositive-polarity pixel signals based on the image data for the secondhorizontal line of the first frame stored in the buffer 11 a. Thehorizontal driver 8 outputs the positive-polarity pixel signalsSIG_(PLUS) for the second horizontal line of the first frame to onegroup of the two groups (the group of the odd-numbered signal lines SLand the group of the even-numbered signal lines SL) of the N signallines SL. The horizontal driver 8 maintains the electric potential(negative-polarity pixel signals SIG_(MINUS) for the first horizontalline of the first frame) of the other group of the two groups of the Nsignal lines SL.

The horizontal driver 8, for example, outputs the positive-polaritypixel signals SIG_(PLUS) for the second horizontal line of the firstframe to the group of the odd-numbered signal lines SL (refer to thesignal lines SL₁, SL₃, SL₅, . . . in FIG. 5) out of the N signal linesSL. The horizontal driver 8 maintains the electric potential(negative-polarity pixel signals SIG_(MINUS) for the first horizontalline of the first frame) of the group of the even-numbered signal linesSL (refer to the signal lines SL₂, SL₄, SL₆, . . . in FIG. 5) out of theN signal lines SL.

From timing t₄₄ to timing t₄₆, the COG 11 outputs the control signalSEL₃ (refer to FIG. 5) at a low level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned off. Consequently,all the drive electrodes COML are brought into a floating state.

Referring back to FIG. 5, when the drive electrode COML₁ is in afloating state, the electric potential of the drive electrode COML₁changes due to the pixel signals SIG_(PLUS) supplied to the signal linesSL₁, SL₃, and SL₅. Because the signal lines SL₁, SL₃, and SL₅ arecapacitively coupled to the detection line RL₁, the detection signalSIG_(RL) is generated in the detection line RL₁ due to the pixel signalsSIG_(PLUS) supplied to the signal lines SL₁, SL₃, and SL₅. The COF 12reads the detection signal SIG_(RL), at a timing based on the timingsignal HSYNC, for example, at timing t₄₅. The COF 12 performs samplingand A/D conversion on the detection signal, thereby obtaining thepositive-polarity detection pixel data. The COF 12 may read the peakvoltage of the detection signal SIG_(RL), thereby obtaining thepositive-polarity detection pixel data.

The period from timing t₄₆ to timing t₄₇ corresponds to the displaywriting (image display) period for the second horizontal line of thefirst frame.

At timing t₄₆, the COG 11 causes the horizontal driver 8 to output thepixel signals based on the image data for the second horizontal line ofthe first frame stored in the buffer 11 a. The horizontal driver 8maintains the electric potential (positive-polarity pixel signalsSIG_(PLUS) for the second horizontal line of the first frame) of onegroup of the two groups (the group of the odd-numbered signal lines SLand the group of the even-numbered signal lines SL) of the N signallines SL. The horizontal driver 8 outputs the negative-polarity pixelsignals SIG_(MINUS) for the second horizontal line of the first frame tothe other group of the two groups of the N signal lines SL.

The horizontal driver 8, for example, maintains the electric potential(positive-polarity pixel signals SIG_(PLUS) for the second horizontalline of the first frame) of the group of the odd-numbered signal linesSL (refer to the signal lines SL₁, SL₃, SL₅, . . . in FIG. 5) out of theN signal lines SL. The horizontal driver 8 outputs the negative-polaritypixel signals SIG_(MINUS) for the second horizontal line of the firstframe to the group of the even-numbered signal lines SL (refer to thesignal lines SL₂, SL₄, SL₆, . . . in FIG. 5) out of the N signal linesSL.

From timing t₄₆ to timing t₄₇, the COG 11 outputs the control signalSEL₃ (refer to FIG. 5) at a high level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned on. The driveelectrode driver 9 outputs the drive signals VCOM to all the driveelectrodes COML. Consequently, an electric field is formed between thepixel electrodes PE (refer to FIG. 4) and the drive electrodes COML,thereby displaying an image.

Similarly, the COG 11 and the COF 12 perform positive-polarity imagedetection and display writing (image display) of the third to M-thhorizontal lines of the first frame.

The period from timing t₄₉ to timing t₅₂ corresponds to anegative-polarity image detection and display writing (image display)period for the first horizontal line of the second frame.

At timing t₄₉, the host HST outputs image data for the first horizontalline of the second frame to the COG 11. The COG 11 temporarily storesthe image data for the first horizontal line of the second framesupplied from the host HST in the buffer 11 a (refer to FIG. 2). Thebuffer 11 a simply needs to have storage capacity large enough to storetherein image data of one horizontal line.

The period from timing t₄₉ to timing t₅₀, which is a predetermined timeafter timing t₄₉, corresponds to a precharge period for the signal linesSL.

From timing t₄₉ to timing t₅₀, the horizontal driver 8 outputs theground potential GND to all the signal lines SL, thereby precharging allthe signal lines SL with the ground potential GND. The period fromtiming t₅₀ to timing t₅₁ corresponds to the negative-polarity imagedetection period for the first horizontal line of the second frame.

At timing t₅₀, the COG 11 causes the horizontal driver 8 to output thenegative-polarity pixel signals for the first horizontal line of thesecond frame based on the image data for the first horizontal line ofthe second frame stored in the buffer 11 a. The horizontal driver 8outputs the negative-polarity pixel signals SIG_(MINUS) for the firsthorizontal line of the second frame to one group of the two groups (thegroup of the odd-numbered signal lines SL and the group of theeven-numbered signal lines SL) of the N signal lines SL. The horizontaldriver 8 maintains the electric potential (ground potential GND) of theother group of the two groups of the N signal lines SL.

The horizontal driver 8, for example, outputs the negative-polaritypixel signals SIG_(MINUS) for the first horizontal line of the secondframe to the group of the even-numbered signal lines SL (refer to thesignal lines SL₂, SL₄, SL₆, . . . in FIG. 5) out of the N signal linesSL. The horizontal driver 8 maintains the electric potential (groundpotential GND) of the group of the odd-numbered signal lines SL (referto the signal lines SL₁, SL₃, SL₅, . . . in FIG. 5) out of the N signallines SL.

From timing t₅₀ to timing t₅₁, the COG 11 outputs the control signalSEL₃ (refer to FIG. 5) at a low level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned off. Consequently,all the drive electrodes COML are brought into a floating state.

Referring back to FIG. 5, when the drive electrode COML₁ is in afloating state, the electric potential of the drive electrode COML₁changes due to the pixel signals SIG_(MINUS) supplied to the signallines SL₂, SL₄, and SL₆. Because the signal lines SL₂, SL₄, and SL₆ arecapacitively coupled to the detection line RL₁, the detection signalSIG_(RL) is generated in the detection line RL₁ due to the pixel signalsSIG_(MINUS) supplied to the signal lines SL₂, SL₄, and SL₆. The COF 12reads the detection signal SIG_(RL), at a timing based on the timingsignal HSYNC, for example, at timing t₅₀. The COF 12 performs samplingand A/D conversion on the detection signal, thereby obtaining thenegative-polarity detection pixel data. The COF 12 may read the peakvoltage of the detection signal SIG L, thereby obtaining thenegative-polarity detection pixel data.

The period from timing t₅₁ to timing t₅₂ corresponds to the displaywriting (image display) period for the first horizontal line of thesecond frame.

At timing t₅₁, the COG 11 causes the horizontal driver 8 to output thepixel signals based on the image data for the first horizontal line ofthe second frame stored in the buffer 11 a. The horizontal driver 8maintains the electric potential (negative-polarity pixel signalsSIG_(MINUS) for the first horizontal line of the second frame) of onegroup of the two groups (the group of the odd-numbered signal lines SLand the group of the even-numbered signal lines SL) of the N signallines SL. The horizontal driver 8 outputs the positive-polarity pixelsignals SIG_(PLUS) for the first horizontal line of the second frame tothe other group of the two groups of the N signal lines SL.

The horizontal driver 8, for example, maintains the electric potential(negative-polarity pixel signals SIG_(MINUS) for the first horizontalline of the second frame) of the group of the even-numbered signal linesSL (refer to the signal lines SL₂, SL₄, SL₆, . . . in FIG. 5) out of theN signal lines SL. The horizontal driver 8 outputs the positive-polaritypixel signals SIG_(PLUS) for the first horizontal line of the secondframe to the group of the odd-numbered signal lines SL (refer to thesignal lines SL₁, SL₃, SL₅, . . . in FIG. 5) out of the N signal linesSL.

From timing t₅₁ to timing t₅₂, the COG 11 outputs the control signalSEL₃ (refer to FIG. 5) at a high level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned on. The driveelectrode driver 9 outputs the drive signals VCOM to all the driveelectrodes COML. Consequently, an electric field is formed between thepixel electrodes PE (refer to FIG. 4) and the drive electrodes COML,thereby displaying an image.

The period after timing t₅₂ corresponds to a negative-polarity imagedetection and display writing (image display) period for the secondhorizontal line of the second frame.

At timing t₅₂, the host HST outputs image data for the second horizontalline of the second frame to the COG 11. The COG 11 temporarily storesthe image data for the second horizontal line of the second framesupplied from the host HST in the buffer 11 a (refer to FIG. 2).

The period from timing t₅₂ to timing t₅₃, which is a predetermined timeafter timing t₅₂, corresponds to a precharge period for the signal linesSL.

From timing t₅₂ to timing t₅₃, the horizontal driver 8 outputs theground potential GND to one group of the two groups (the group of theodd-numbered signal lines SL and the group of the even-numbered signallines SL) of the N signal lines SL. The horizontal driver 8 thusprecharges the group of the odd-numbered or the even-numbered signallines SL in the N signal lines SL with the ground potential GND. Fromtiming t₅₂ to timing t₅₃, the horizontal driver 8 maintains the electricpotential (positive-polarity pixel signals SIG_(PLUS) for the firsthorizontal line of the second frame) of the other group of the twogroups of the N signal lines SL.

The horizontal driver 8, for example, outputs the ground potential GNDto the group of the even-numbered signal lines SL (refer to the signallines SL₂, SL₄, SL₆, . . . in FIG. 5) out of the N signal lines SL. Thehorizontal driver 8 maintains the electric potential (positive-polaritypixel signals SIG_(PLUS) for the first horizontal line of the secondframe) of the group of the odd-numbered signal lines SL (refer to thesignal lines SL₁, SL₃, SL₅, . . . in FIG. 5) out of the N signal linesSL.

The period from timing t₅₃ to timing t₅₄ corresponds to thenegative-polarity image detection period for the second horizontal lineof the second frame.

At timing t₅₃, the COG 11 causes the horizontal driver 8 to output thenegative-polarity pixel signals based on the image data for the secondhorizontal line of the second frame stored in the buffer 11 a. Thehorizontal driver 8 outputs the negative-polarity pixel signalsSIG_(MINUS) for the second horizontal line of the second frame to onegroup of the two groups (the group of the odd-numbered signal lines SLand the group of the even-numbered signal lines SL) of the N signallines SL. The horizontal driver 8 maintains the electric potential(positive-polarity pixel signals SIG_(PLUS) for the first horizontalline of the second frame) of the other group of the two groups of the Nsignal lines SL.

The horizontal driver 8, for example, outputs the negative-polaritypixel signals SIG_(MINUS) for the second horizontal line of the secondframe to the group of the even-numbered signal lines SL (refer to thesignal lines SL₂, SL₄, SL₆, . . . in FIG. 5) out of the N signal linesSL. The horizontal driver 8 maintains the electric potential(positive-polarity pixel signals SIG_(PLUS) for the first horizontalline of the second frame) of the group of the odd-numbered signal linesSL (refer to the signal lines SL₁, SL₃, SL₅, . . . in FIG. 5) out of theN signal lines SL.

From timing t₅₂ to timing t₅₄, the COG 11 outputs the control signalSEL₃ (refer to FIG. 5) at a low level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned off. Consequently,all the drive electrodes COML are brought into a floating state.

Referring back to FIG. 5, when the drive electrode COML₁ is in afloating state, the electric potential of the drive electrode COML₁changes due to the pixel signals SIG_(MINUS) supplied to the signallines SL₂, SL₄, and SL₆. Because the signal lines SL₂, SL₄, and SL₆ arecapacitively coupled to the detection line RL₁, the detection signalSIG_(RL) is generated in the detection line RL₁ due to the pixel signalsSIG_(MINUS) supplied to the signal lines SL₂, SL₄, and SL₆. The COF 12reads the detection signal SIG_(RL), at a timing based on the timingsignal HSYNC, for example, at timing t₅₃. The COF 12 performs samplingand A/D conversion on the detection signal, thereby obtaining thenegative-polarity detection pixel data. The COF 12 may read the peakvoltage of the detection signal SIG_(RL), thereby obtaining thenegative-polarity detection pixel data.

The period after timing t₅₄ corresponds to a display writing (imagedisplay) period for the second horizontal line of the second frame.

At timing t₅₄, the COG 11 causes the horizontal driver 8 to output thepixel signals based on the image data for the second horizontal line ofthe second frame stored in the buffer 11 a. The horizontal driver 8maintains the electric potential (negative-polarity pixel signalsSIG_(MINUS) for the second horizontal line of the second frame) of onegroup of the two groups (the group of the odd-numbered signal lines SLand the group of the even-numbered signal lines SL) of the N signallines SL. The horizontal driver 8 outputs the positive-polarity pixelsignals SIG_(PLUS) for the second horizontal line of the second frame tothe other group of the two groups of the N signal lines SL.

The horizontal driver 8, for example, maintains the electric potential(negative-polarity pixel signals SIG_(MINUS) for the second horizontalline of the second frame) of the group of the even-numbered signal linesSL (refer to the signal lines SL₂, SL₄, SL₆, . . . in FIG. 5) out of theN signal lines SL. The horizontal driver 8 outputs the positive-polaritypixel signals SIG_(PLUS) for the second horizontal line of the secondframe to the group of the odd-numbered signal lines SL (refer to thesignal lines SL₁, SL₃, SL₅, . . . in FIG. 5) out of the N signal linesSL.

From timing t₅₄, the COG 11 outputs the control signal SEL₃ (refer toFIG. 5) at a high level to the drive electrode driver 9. As a result,the switches SW₂₁ and SW₂₂ are turned on. The drive electrode driver 9outputs the drive signals VCOM to all the drive electrodes COML.Consequently, an electric field is formed between the pixel electrodesPE (refer to FIG. 4) and the drive electrodes COML, thereby displayingan image.

Similarly, the COG 11 and the COF 12 perform negative-polarity imagedetection and display writing (image display) of the third e to M-thhorizontal lines of the second frame.

As described above, the number of pieces of detection pixel data in oneline of the detection image data is (N/2). As illustrated in FIG. 12,the display apparatus 1 performs image detection on a line-by-linebasis. Consequently, the detection image data includes M×(N/2) pieces ofpixel data.

FIG. 13 is a flowchart of an operation in the second exemplary operationperformed by the display apparatus according to the first embodiment.The display apparatus 1 performs the operation illustrated in FIG. 13 ona frame-by-frame basis.

At Step S200, the host HST initializes a variable i to 1. The variable iindicates the number of the line to be subjected to image detection anddisplay writing (image display).

At Step S202, the host HST transmits image data for the i-th horizontalline to the COG

At Step S204, the COF 12 detects a positive- or negative-polarity imageof the i-th horizontal line.

At Step S206, the host HST reads positive- or negative-polaritydetection image data of the i-th horizontal line from the COF 12.

At Step S208, the COG 11 displays an image of the i-th horizontal line.

At Step S210, the host HST determines whether the variable i is equal toM. If the host HST determines that the variable i is not equal to M (Noat Step S210), the host HST performs the processing at Step S212. If thehost HST determines that the variable i is equal to M (Yes at StepS210), the host HST performs the processing at Step S214.

If the host HST determines that the variable i is not equal to M (No atStep S210), the host HST increments the variable i at Step S212 andperforms the processing at Step S202 again.

Explanation of the processing from Step S214 to Step S224 is omittedbecause it is the same as the processing from Step S114 to Step S124(refer to FIG. 10) in the first exemplary operation.

The display apparatus 1 has the following characteristics. The displayapparatus 1 also has characteristics other than those described below.The detection lines RL of the detector DET are capacitively coupled tothe signal lines SL of the display device DSP. The detection signals aregenerated in the detection lines RL due to the pixel signals supplied tothe signal lines SL. If no problem occurs in the paths from the COG 11to the signal lines SL via the horizontal driver 8, the detection imagedata matches the image data. By contrast, if a problem occurs in thepaths from the COG 11 to the signal lines SL via the horizontal driver8, the detection image data does not match the image data. Consequently,the display apparatus 1 can determine whether any problem occurs in thepaths from the COG 11 to the signal lines SL via the horizontal driver 8based on the detection image data, thereby enhancing the safety.

If a problem occurs in a pixel Pix positioned downstream of the signallines SL, the display apparatus 1 fails to detect the problem occurringin the pixel Pix. If a problem occurs in a pixel Pix, however, only onedot in the image is affected by the problem, resulting in a slighteffect on the safety. By contrast, if a problem occurs in a path fromthe COG 11 to a signal line SL via the horizontal driver 8, one columnin the image is affected by the problem, resulting in a larger effect onthe safety. The display apparatus 1 can determine whether any problemoccurs in the paths from the COG 11 to the signal lines SL via thehorizontal driver 8, thereby enhancing the safety.

The display apparatus 1 detects an image using the detection lines RLdisposed in a layer different from that of the signal lines SL. Withthis configuration, the pixels Pix do not include the detector of theliquid crystal display device disclosed in JP-A-2009-276612.Consequently, the display apparatus 1 can provide desiredhigh-definition display. Unlike the liquid crystal display devicedisclosed in JP-A-2009-276612, the display apparatus 1 includes neitherthe X driver for measurement nor the Y driver for measurement.Consequently, the display apparatus 1 requires a smaller number ofcircuits, has a smaller size, and can be manufactured at a lower cost.

The structure of the panel PNL (refer to FIGS. 2 and 4) has features incommon with the structures of widely spread mutual capacitive displayapparatuses with a touch detection function. As illustrated in FIG. 2,the extending direction of the detection lines RL is the same as that ofthe drive electrodes COML in the display apparatus 1. By contrast, in adisplay apparatus with a touch detection function, the extendingdirection of touch detection lines intersects that of drive electrodes.A touch is detected at the intersections of the drive electrodes and thetouch detection lines. As illustrated in FIG. 4, the layer of thedetection lines RL is the same as that of the detection lines of adisplay apparatus with a touch detection function. Consequently, thepanel PNL can be manufactured by changing the extending direction of thedetection lines of a display apparatus with a touch detection function.In other words, the panel PNL can be manufactured using themanufacturing process for a display apparatus with a touch detectionfunction. Consequently, the panel PNL can be manufactured at lowerdevelopment and manufacturing costs.

The COF 12 has features in common with a touch IC of a displayapparatuses with a touch detection function. As illustrated in FIG. 2,the COF 12 is coupled to the detection lines RL and reads the detectionsignals generated in the detection lines RL. In other words, the COF 12can be manufactured using part or all of the touch IC of a displayapparatus with a touch detection function. Consequently, the COF 12 canbe manufactured at lower development and manufacturing costs. Thedisplay apparatus 1 may supply a positive- or negative-polarity signalto at least one signal line SL and detect a detection signal with atleast one detection line RL corresponding to the at least one signalline SL supplied with the positive- or negative-polarity signal.

1-3. Modifications

While the first embodiment describes a case where the present inventionis applied to a lateral electric field mode liquid crystal displayapparatus, the present invention is not necessarily applied thereto. Thepresent invention is also applicable to a vertical electric field modeliquid crystal display apparatus. Examples of the modes of the verticalelectric field mode liquid crystal display apparatus include, but arenot limited to, a twisted nematic (TN) mode, a vertical alignment (VA)mode, an electrically controlled birefringence (ECB) mode, etc.

FIG. 14 is a schematic diagram of a sectional structure of a panel of adisplay apparatus according to a modification of the first embodiment.FIG. 14 is a schematic diagram of a sectional structure of three pixelsPix.

A panel PNLa is an in-cell apparatus in which the detector DET isintegrated with the display device DSP.

The panel PNLa includes a first substrate 5 a, a second substrate 6 a,and the liquid crystal LC. The second substrate 6 a faces the firstsubstrate 5 a. The liquid crystal LC is disposed between the firstsubstrate 5 a and the second substrate 6 a.

The first substrate 5 a includes the substrate 31 serving as atranslucent insulation substrate. The polarization plate 32 is disposedon the surface of the substrate 31 facing in the opposite direction ofthe Z-direction.

The scanning line GL serving as a metal layer is provided on the surfaceof the substrate 31 facing in the Z-direction. The scanning line GLextends in the X-direction (horizontal direction in FIG. 14). Theinsulation layer 33 is provided on the scanning line GL in theZ-direction. The TFT elements Tr (refer to FIG. 3), which are notillustrated in FIG. 14, may be provided between the scanning line GL andthe insulation layer 33.

Pixel electrodes PE₁ to PE₉, which serve as a transparent conductivefilm layer, and signal lines SL₁ to SL₉ are alternately provided on asurface of the insulation layer 33 facing in the Z-direction. The signallines SL extend in the Y-direction (direction perpendicular to the planeof FIG. 14).

The second substrate 6 a includes the substrate 41 serving as atranslucent insulation substrate. A color area 22R₁ colored in red (R),a color area 22G₁ colored in green (G), a color area 22B₁ colored inblue (B), a color area 22R₂ colored in R, a color area 22G₂ colored inG, a color area 22B₂ colored in B, a color area 22R₃ colored in R, acolor area 22G₃ colored in G, and a color area 22B₃ colored in B areprovided on the surface of the substrate 41 facing in the oppositedirection of in the Z-direction.

The drive electrode COML₁ is provided on surfaces of the color areas22R₁, 22G₁, and 22B₁ facing in the opposite direction of theZ-direction. The drive electrode COML₁ extends in the Y-direction(direction perpendicular to the plane of FIG. 14).

The drive electrode COML₂ is provided on surfaces of the color areas22R₂, 22G₂, and 22B₂ facing in the opposite direction of theZ-direction. The drive electrode COML₂ extends in the Y-direction(direction perpendicular to the plane of FIG. 14).

The drive electrode COML₃ is provided on surfaces of the color areas22R₃, 22G₃, and 22B₃ facing in the opposite direction of theZ-direction. The drive electrode COML₃ extends in the Y-direction(direction perpendicular to the plane of FIG. 14).

Detection lines RL₁ to RL₃ are provided on the surface of the substrate41 facing in the Z-direction. The detection lines RL₁ to RL₃ extend inthe Y-direction (direction perpendicular to the plane of FIG. 14). Thedetection lines RL₁ to RL₃ correspond to the detector DET illustrated inFIG. 1.

The polarization plate 42 is disposed on the detection lines RL₁ to RL₃in the Z-direction. The polarization plate 42 allows only polarizationcomponents having a certain polarization direction in the light havingpassed through the liquid crystal LC to pass therethrough. Thetranslucent cover member 44 is disposed in the Z-direction with respectto the polarization plate 42. The cover member 44 is made of a glass ora resin, for example.

An electric field is formed between the drive electrode COML₁ and eachof the pixel electrodes PE₁, PE₂, PE₃. The electric field causes themolecules of the liquid crystal LC to rise and fall along theZ-direction, thereby rotating the polarization direction of light havingpassed through the polarization plate 32. An electric field is formedbetween the drive electrode COML₂ and each of the pixel electrodes PE₄,PE₅, and PE₆. The electric field causes the molecules of the liquidcrystal LC to rise and fall along the Z-direction, thereby rotating thepolarization direction of light having passed through the polarizationplate 32. An electric field is formed between the drive electrode COML₃and each of the pixel electrodes PE₇, PE₈, and PE₉. The electric fieldcauses the molecules of the liquid crystal LC to rise and fall along theZ-direction, thereby rotating the polarization direction of light havingpassed through the polarization plate 32. In other words, the panel PNLais a vertical electric field mode liquid crystal display apparatus.

2. Second Embodiment

FIG. 15 is a diagram of the module configuration of a display apparatusaccording to a second embodiment. In the second and subsequentembodiments, description of elements common to the first embodiment isappropriately omitted.

A panel PNLb includes a substrate 4 b, the COG 11 serving as a driverIC, and the COF 12 serving as a detection IC. The substrate 4 b includesa first substrate 5 b and a second substrate 6 b. The second substrate 6b is disposed in the Z-direction with respect to the first substrate 5 band faces the first substrate 5 b with a predetermined space interposedtherebetween.

The substrate 4 b has the display area DA and the peripheral area GD. Inthe display area DA, a plurality of pixels Pix including liquid crystalelements are disposed in a matrix (row-column configuration). Theperipheral area GD is positioned outside the display area DA. Theperipheral area GD is provided with the vertical driver (vertical drivecircuit) 7, the horizontal driver (horizontal drive circuit) 8, and thedrive electrode driver 9.

The COG 11 is mounted on the first substrate 5 b and controls thevertical driver 7, the horizontal driver 8, and the drive electrodedriver 9. The COF 12 is mounted on the FPC T coupled to the firstsubstrate 5 b. The COG 11 and the COF 12 are coupled to the host HST(refer to FIG. 1) via the FPC T. The COG 11 includes the buffer 11 athat temporarily stores therein image data supplied from the host HST.

The display area DA has a matrix (row-column) configuration in which thepixels Pix are arrayed in M-rows and N-columns. The display area DA isprovided with the scanning lines GL and the signal lines SL. Thescanning lines GL are provided for the respective rows in the array ofM×N pixels Pix and extend in the X-direction. The signal lines SL areprovided for the respective columns and extend in the Y-direction. Inother words, the number of scanning lines GL is M, and the number ofsignal lines SL is N.

The display area DA is also provided with drive electrodes COML. Thedrive electrodes COML extending in the Y-direction are arranged one forevery two columns of the pixels Pix. In other words, the number of driveelectrodes COML is (N/2). The configuration described above is given byway of example only, and the drive electrodes COML are not necessarilyarranged one for every two columns of the pixels Pix.

The drive electrode COML is made of a transparent material and shared bythe pixels Pix of at least one column, for example. The drive electrodesCOML are coupled to the drive electrode driver 9. In the image displayperiod, the drive electrode driver 9 supplies the constant drive signalsVCOM to the drive electrodes COML. In the image detection period, thedrive electrode driver 9 brings the drive electrodes COML into afloating state (high-impedance state). In the image display period, thedrive electrodes COML generate an electric field for driving the liquidcrystals between the drive electrodes COML and the pixel electrodes PE(refer to FIG. 3).

The drive electrodes COML according to the present embodiment arecapacitively coupled to the signal lines SL. In the image detectionperiod, the drive electrodes COML generate detection signals due to thepixel signals supplied to the signal lines SL.

The drive electrodes COML according to the present embodiment correspondto the detector DET illustrated in FIG. 1.

The COF 12 is coupled to the drive electrodes COML. In the imagedetection period, the COF 12 outputs detection image data to the hostHST based on the detection signals generated in the drive electrodesCOML due to the pixel signals. The drive electrodes COML according tothe present embodiment are arranged one for every two columns of thepixels Pix. In other words, the number of pieces of detection pixel datain one line of the detection image data is (N/2). The configurationdescribed above is given by way of example only, and the driveelectrodes COML are not necessarily arranged one for every two columnsof the pixels Pix. The drive electrodes COML may be arranged one forevery one or every three or more columns of the pixels Pix.

FIG. 16 is a schematic diagram of a sectional structure of a panel ofthe display apparatus according to the second embodiment. FIG. 16 is aschematic diagram of a sectional structure of one pixel Pix.

The panel PNLb is an in-cell apparatus in which the detector DET isintegrated with the display device DSP. The panel PNLb includes thefirst substrate 5 b, the second substrate 6 b, and the liquid crystalLC. The second substrate 6 b faces the first substrate 5 b. The liquidcrystal LC is disposed between the first substrate 5 b and the secondsubstrate 6 b.

Explanation of the configuration of the first substrate 5 b is omittedbecause it is the same as the configuration of the first substrate 5according to the first embodiment.

The configuration of the second substrate 6 b is different from that ofthe second substrate 6 according to the first embodiment in that nodetection line RL is provided.

FIG. 17 is a diagram of the configuration of the horizontal driver, thedrive electrode driver, and the COF of the display apparatus accordingto the second embodiment. FIG. 17 illustrates a portion of thehorizontal driver 8 that drives the pixels Pix of four columns, aportion of the drive electrode driver 9 that drives the pixels Pix offour columns, and a portion of the COF 12 that reads detection signalsof the pixels Pix of four columns.

The switch SW₂₁ is disposed between the amplifier COMAMP serving as adrive circuit and the drive electrode COML₁. When the control signalSEL₃ supplied from the COG 11 (refer to FIG. 15) is at a high level, theswitch SW₂₁ electrically couples the amplifier COMAMP to the driveelectrode COML₁. When the control signal SEL₃ is at a low level, theswitch SW₂₁ cuts off electrical coupling between the amplifier COMAMPand the drive electrode COML₁.

In the image display period, the control signal SEL₃ is at a high level.As a result, the switch SW₂₁ electrically couples the amplifier COMAMPto the drive electrode COML₁, thereby supplying the drive signal VCOM tothe drive electrode COML₁. In the image detection period, the controlsignal SEL₃ is at a low level. As a result, the switch SW₂₁ cuts offelectrical coupling between the amplifier COMAMP and the drive electrodeCOML₁, thereby supplying no drive signal VCOM to the drive electrodeCOML₁.

A switch SW₂₂ is disposed between the amplifier COMAMP and the driveelectrode COML₂. When a control signal SEL₃ supplied from the COG 11(refer to FIG. 15) is at a high level, the switch SW₂₂ electricallycouples the amplifier COMAMP to the drive electrode COML₂. When thecontrol signal SEL₃ is at a low level, the switch SW₂₂ cuts offelectrical coupling between the amplifier COMAMP and the drive electrodeCOML₂.

In the image display period, the control signal SEL₃ is at a high level.As a result, the switch SW₂₂ electrically couples the amplifier COMAMPto the drive electrode COML₂, thereby supplying the drive signal VCOM tothe drive electrode COML₂. In the image detection period, the controlsignal SEL₃ is at a low level. As a result, the switch SW₂₂ cuts offelectrical coupling between the amplifier COMAMP and the drive electrodeCOML₂, thereby supplying no drive signal VCOM to the drive electrodeCOML₂.

The drive electrodes COML according to the present embodiment arearranged one for every two columns of the pixels Pix. In the imagedisplay period, the drive electrode COML₁ supplies the drive signalsVCOM to the pixels Pix in the first and the second columns. In the imagedisplay period, the drive electrode COML₂ supplies the drive signalsVCOM to the pixels Pix in the third and the fourth columns.

The drive electrodes COML according to the present embodiment arearranged one for every two columns of the pixels Pix. The driveelectrode COML₁ is capacitively coupled to the signal lines SL₁ to SL₆.In the image detection period, the drive electrode COML₁ generatesdetection signal due to the pixel signals supplied to the signal linesSL₁ to SL₆. The drive electrode COML₂ is capacitively coupled to thesignal lines SL₇ to SL₁₂ to generate detection signal due to the pixelsignals supplied to the signal lines SL₇ to SL₁₂.

The COF 12 (refer to FIG. 15) includes detection circuits INT₁ and INT₂serving as integration circuits. A switch SW₃₁ is disposed between thedetection circuit INT₁ and the drive electrode COML₁. When a controlsignal SEL₄ supplied from the COG 11 (refer to FIG. 15) is at a highlevel, the switch SW₃₁ electrically couples the detection circuit INT₁to the drive electrode COML₁. When the control signal SEL₄ is at a lowlevel, the switch SW₃₁ cuts off electrical coupling between thedetection circuit INT₁ and the drive electrode COML₁.

In the image display period, the control signal SEL₄ is at a low level.As a result, the switch SW₃₁ cuts off electrical coupling between thedetection circuit INT₁ and the drive electrode COML₁. In the imagedetection period, the control signal SEL₄ is at a high level. As aresult, the switch SW₃₁ electrically couples the detection circuit INT₁to the drive electrode COML₁, thereby supplying the detection signal tothe detection circuit INT₁. The detection circuit INT₁ compares thedetection signal with a reference potential Vref to read the detectionsignal.

A switch SW₃₂ is disposed between the detection circuit INT₂ and thedrive electrode COML₂. When the control signal SEL₄ supplied from theCOG 11 (refer to FIG. 15) is at a high level, the switch SW₃₂electrically couples the detection circuit INT₂ to the drive electrodeCOML₂. When the control signal SEL₄ is at a low level, the switch SW₃₂cuts off electrical coupling between the detection circuit INT₂ and thedrive electrode COML₂.

In the image display period, the control signal SEL₄ is at a low level.As a result, the switch SW₃₂ cuts off electrical coupling between thedetection circuit INT₂ and the drive electrode COML₂. In the imagedetection period, the control signal SEL₄ is at a high level. As aresult, the switch SW₃₂ electrically couples the detection circuit INT₂to the drive electrode COML₂, thereby supplying the detection signal tothe detection circuit INT₂. The detection circuit INT₂ compares thedetection signal with a reference potential Vref to read the detectionsignal.

2-1. Exemplary Operation Performed by the Display Apparatus According tothe Second Embodiment

The following describes an exemplary operation performed by the displayapparatus according to the second embodiment. In the present exemplaryoperation, the display apparatus performs image display and imagedetection row by row.

FIG. 18 is a diagram of an operating timing in an exemplary operationperformed by the display apparatus according to the second embodiment.

The period from timing t₆₀ of the first rising edge of the timing signalTSVD to timing t₆₈ of the second rising edge of the timing signal TSVDcorresponds to the period of image display and image detection of thefirst frame. The period after timing t₆₈ of the second rising edge ofthe timing signal TSVD corresponds to the period of image display andimage detection of the second frame.

A timing signal HSYNC for detection control output from the COG 11 tothe COF 12 has the same frequency as that of the horizontalsynchronization signal for display control of displaying an image on thedisplay device DSP by the COG 11, for example.

During the entire period, the COG 11 outputs the control signals SEL₁and SEL₂ (refer to FIG. 17) at a high level to the horizontal driver 8.As a result, the switches SW₁ to SW₁₂ are turned on.

The period from timing t₆₁ to timing t₆₄ corresponds to apositive-polarity image detection and display writing (image display)period for the first horizontal line of the first frame.

At timing t₆₁, the host HST outputs image data for the first horizontalline of the first frame to the COG 11. The COG 11 temporarily stores theimage data for the first horizontal line of the first frame suppliedfrom the host HST in the buffer 11 a (refer to FIG. 15). The buffer 11 asimply needs to have storage capacity large enough to store thereinimage data of one horizontal line.

The period from timing t₆₁ to timing t₆₂, which is a predetermined timeafter timing t₆₁, corresponds to a precharge period for the signal linesSL and the drive electrodes COML.

From timing t₆₁ to timing t₆₂, the horizontal driver 8 outputs theground potential GND to all the signal lines SL, thereby precharging allthe signal lines SL with the ground potential GND.

From timing t₆₁ to timing t₆₂, the COG 11 outputs the control signalSEL₃ at a high level to the drive electrode driver 9. From timing t₆₁ totiming t₆₂, the amplifier COMAMP outputs the drive signals VCOM at ahigh level (reference potential Vref) to all the drive electrodes COML,thereby precharging all the drive electrodes COML at a high level(reference potential Vref).

The period from timing t₆₂ to timing t₆₃ corresponds to thepositive-polarity image detection period for the first horizontal lineof the first frame.

At timing t₆₂, the COG 11 causes the horizontal driver 8 to output thepositive-polarity pixel signals for the first horizontal line of thefirst frame based on the image data for the first horizontal line of thefirst frame stored in the buffer 11 a. The horizontal driver 8 outputsthe positive-polarity pixel signals SIG_(PLUS) for the first horizontalline of the first frame to one group of the two groups (the group of theodd-numbered signal lines SL and the group of the even-numbered signallines SL) of the N signal lines SL. The horizontal driver 8 maintainsthe electric potential (ground potential GND) of the other group of thetwo groups of the N signal lines SL.

The horizontal driver 8, for example, outputs the positive-polaritypixel signals SIG_(PLUS) for the first horizontal line of the firstframe to the group of the odd-numbered signal lines SL (refer to thesignal lines SL₁, SL₃, SL₅, . . . in FIG. 17) out of the N signal linesSL. The horizontal driver 8 maintains the electric potential (groundpotential GND) of the group of the even-numbered signal lines SL (referto the signal lines SL₂, SL₄, SL₆, . . . in FIG. 17) out of the N signallines SL.

From timing t₆₂ to timing t₆₃, the COG 11 outputs the control signalSEL₃ (refer to FIG. 17) at a low level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned off. Consequently,all the drive electrodes COML are brought into a floating state fromtiming t₆₂ to timing t₆₃.

Referring back to FIG. 17, when the drive electrode COML₁ is in afloating state, the signal lines SL₁, SL₃, and SL₅ are capacitivelycoupled to the drive electrode COML₁. As a result, the detection signalis generated in the drive electrode COML₁ due to the pixel signalsSIG_(PLUS) supplied to the signal lines SL₁, SL₃, and SL₅. Subsequently,the voltage of the drive electrode COML₁ returns to a voltagecorresponding to the reference potential (Vref) of an operationalamplifier included in the detection circuit of the COF 12. The COG 11changes the control signal SEL₄ to a high level at a timing based on thetiming signal HSYNC, for example, at timing t₆₂. As a result, the switchSW₃₁ is turned on at timing t₆₂. The detection circuit INT₁ reads thedetection signal at timing t₆₂. The COF 12 performs sampling and A/Dconversion on the detection signal, thereby obtaining thepositive-polarity detection pixel data. The detection signal is a spikesignal. The COF 12 may read the peak voltage of the detection signal,thereby obtaining the positive-polarity detection pixel data.

The period from timing t₆₃ to timing t₆₄ corresponds to the displaywriting (image display) period for the first horizontal line of thefirst frame.

At timing t₆₃, the COG 11 causes the horizontal driver 8 to output thepixel signals based on the image data for the first horizontal line ofthe first frame stored in the buffer 11 a. The horizontal driver 8maintains the electric potential (positive-polarity pixel signalsSIG_(PLUS) for the first horizontal line of the first frame) of onegroup of the two groups (the group of the odd-numbered signal lines SLand the group of the even-numbered signal lines SL) of the N signallines SL. The horizontal driver 8 outputs the negative-polarity pixelsignals SIG_(MINUS) for the first horizontal line of the first frame tothe other group of the two groups of the N signal lines SL.

The horizontal driver 8, for example, maintains the electric potential(positive-polarity pixel signals SIG_(PLUS) for the first horizontalline of the first frame) of the group of the odd-numbered signal linesSL (refer to the signal lines SL₁, SL₃, SL₅, . . . in FIG. 17) out ofthe N signal lines SL. The horizontal driver 8 outputs thenegative-polarity pixel signals SIG_(MINUS) for the first horizontalline of the first frame to the group of the even-numbered signal linesSL (refer to the signal lines SL₂, SL₄, SL₆, . . . in FIG. 17) out ofthe N signal lines SL.

From timing t₆₃ to timing t₆₄, the COG 11 outputs the control signalSEL₃ (refer to FIG. 17) at a high level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned on. The driveelectrode driver 9 outputs the drive signals VCOM at a low level(electric potential VCOMDC) to all the drive electrodes COML.Consequently, an electric field is formed between the pixel electrodesPE (refer to FIG. 3) and the drive electrodes COML, thereby displayingan image.

From timing t₆₃ to timing t₆₄, the COG 11 changes the control signalSEL₄ (refer to FIG. 17) to a low level. As a result, the switches SW₃₁and SW₃₂ are turned off, whereby neither the detection circuit INT₁ northe detection circuit INT₂ reads the drive signals VCOM at a low level(electric potential VCOMDC).

The period from timing t₆₄ to timing t₆₇ corresponds to apositive-polarity image detection and display writing (image display)period for the second horizontal line of the first frame.

At timing t₆₄, the host HST outputs image data for the second horizontalline of the first frame to the COG 11. The COG 11 temporarily stores theimage data for the second horizontal line of the first frame suppliedfrom the host HST in the buffer 11 a (refer to FIG. 17).

The period from timing t₆₄ to timing t₆₅, which is a predetermined timeafter timing t₆₄, corresponds to a precharge period for the signal linesSL and the drive electrodes COML.

From timing t₆₄ to timing t₆₅, the horizontal driver 8 outputs theground potential GND to one group of the two groups (the group of theodd-numbered signal lines SL and the group of the even-numbered signallines SL) of the N signal lines SL. The horizontal driver 8 thusprecharges the group of the odd-numbered or the even-numbered signallines SL in the N signal lines SL with the ground potential GND. Fromtiming t₆₄ to timing t₆₅, the horizontal driver 8 maintains the electricpotential (negative-polarity pixel signals SIG_(MINUS) for the firsthorizontal line of the first frame) of the other group of the two groupsof the N signal lines SL.

The horizontal driver 8, for example, outputs the ground potential GNDto the group of the odd-numbered signal lines SL (refer to the signallines SL₁, SL₃, SL₅, . . . in FIG. 17) out of the N signal lines SL. Thehorizontal driver 8 maintains the electric potential (negative-polaritypixel signals SIG_(MINUS) for the first horizontal line of the firstframe) of the group of the even-numbered signal lines SL (refer to thesignal lines SL₂, SL₄, SL₆, . . . in FIG. 17) out of the N signal linesSL.

From timing t₆₄ to timing t₆₅, the COG 11 outputs the control signalSEL₃ at a high level to the drive electrode driver 9. From timing t₆₄ totiming t₆₅, the amplifier COMAMP outputs the drive signals VCOM at ahigh level (reference potential Vref) to all the drive electrodes COML,thereby precharging all the drive electrodes COML at a high level(reference potential Vref).

The period from timing t₆₅ to timing t₆₆ corresponds to thepositive-polarity image detection period for the second horizontal lineof the first frame.

At timing t₆₅, the COG 11 causes the horizontal driver 8 to output thepositive-polarity pixel signals based on the image data for the secondhorizontal line of the first frame stored in the buffer 11 a. Thehorizontal driver 8 outputs the positive-polarity pixel signalsSIG_(PLUS) for the second horizontal line of the first frame to onegroup of the two groups (the group of the odd-numbered signal lines SLand the group of the even-numbered signal lines SL) of the N signallines SL. The horizontal driver 8 maintains the electric potential(negative-polarity pixel signals SIG_(MINUS) for the first horizontalline of the first frame) of the other group of the two groups of the Nsignal lines SL.

The horizontal driver 8, for example, outputs the positive-polaritypixel signals SIG_(PLUS) for the second horizontal line of the firstframe to the group of the odd-numbered signal lines SL (refer to thesignal lines SL₁, SL₃, SL₅, . . . in FIG. 17) out of the N signal linesSL. The horizontal driver 8 maintains the electric potential(negative-polarity pixel signals SIG_(MINUS) for the first horizontalline of the first frame) of the group of the even-numbered signal linesSL (refer to the signal lines SL₂, SL₄, SL₆, . . . in FIG. 17) out ofthe N signal lines SL.

From timing t₆₅ to timing t₆₆, the COG 11 outputs the control signalSEL₃ (refer to FIG. 17) at a low level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned off. Consequently,all the drive electrodes COML are brought into a floating state fromtiming t₆₅ to timing t₆₆.

Referring back to FIG. 17, when the drive electrode COML₁ is in afloating state, the signal lines SL₁, SL₃, and SL₅ are capacitivelycoupled to the drive electrode COML₁. As a result, the detection signalis generated in the drive electrode COML₁ due to the pixel signalsSIG_(PLUS) supplied to the signal lines SL₁, SL₃, and SL₅. Subsequently,the voltage level of the drive electrode COML₁ returns to a voltagelevel corresponding to the reference potential (Vref) of an operationalamplifier included in the detection circuit of the COF 12. The COG 11changes the control signal SEL₄ to a high level at a timing based on thetiming signal HSYNC, for example, at timing t₆₅. As a result, the switchSW₃₁ is turned on at timing t₆₅. The detection circuit INT₁ reads thedetection signal at timing t₆₅. The COF 12 performs sampling and A/Dconversion on the detection signal, thereby obtaining thepositive-polarity detection pixel data. The COF 12 may read the peakvoltage of the detection signal, thereby obtaining the positive-polaritydetection pixel data.

The period from timing t₆₆ to timing t₆₇ corresponds to the displaywriting (image display) period for the second horizontal line of thefirst frame.

At timing t₆₆, the COG 11 causes the horizontal driver 8 to output thepixel signals based on the image data for the second horizontal line ofthe first frame stored in the buffer 11 a. The horizontal driver 8maintains the electric potential (positive-polarity pixel signalsSIG_(PLUS) for the second horizontal line of the first frame) of onegroup of the two groups (the group of the odd-numbered signal lines SLand the group of the even-numbered signal lines SL) of the N signallines SL. The horizontal driver 8 outputs the negative-polarity pixelsignals SIG_(MINUS) for the second horizontal line of the first frame tothe other group of the two groups of the N signal lines SL.

The horizontal driver 8, for example, maintains the electric potential(positive-polarity pixel signals SIG_(PLUS) for the second horizontalline of the first frame) of the group of the odd-numbered signal linesSL (refer to the signal lines SL₁, SL₃, SL₅, . . . in FIG. 17) out ofthe N signal lines SL. The horizontal driver 8 outputs thenegative-polarity pixel signals SIG_(MINUS) for the second horizontalline of the first frame to the group of the even-numbered signal linesSL (refer to the signal lines SL₂, SL₄, SL₆, . . . in FIG. 17) out ofthe N signal lines SL.

From timing t₆₆ to timing t₆₇, the COG 11 outputs the control signalSEL₃ (refer to FIG. 17) at a high level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned on. The driveelectrode driver 9 outputs the drive signals VCOM at a low level(electric potential VCOMDC) to all the drive electrodes COML.Consequently, an electric field is formed between the pixel electrodesPE (refer to FIG. 3) and the drive electrodes COML, thereby displayingan image.

From timing t₆₆ to timing t₆₇, the COG 11 changes the control signalSEL₄ (refer to FIG. 17) to a low level. As a result, the switch SW₃₁ isturned off, whereby the detection circuit INT₁ does not read the drivesignals VCOM at a low level (electric potential VCOMDC).

Similarly, the COG 11 and the COF 12 perform positive-polarity imagedetection and display writing (image display) of the third to M-thhorizontal lines of the first frame.

The period from timing t₆₉ to timing t₇₂ corresponds to anegative-polarity image detection and display writing (image display)period for the first horizontal line of the second frame.

At timing t₆₉, the host HST outputs image data for the first horizontalline of the second frame to the COG 11. The COG 11 temporarily storesthe image data for the first horizontal line of the second framesupplied from the host HST in the buffer 11 a (refer to FIG. 15). Thebuffer 11 a simply needs to have storage capacity large enough to storetherein image data of one horizontal line.

The period from timing t₆₉ to timing to, which is a predetermined timeafter timing t₆₉, corresponds to a precharge period for the signal linesSL and the drive electrodes COML.

From timing t₆₉ to timing to, the horizontal driver 8 outputs the groundpotential GND to all the signal lines SL, thereby precharging all thesignal lines SL with the ground potential GND.

From timing t₆₉ to timing to, the COG 11 outputs the control signal SEL₃at a high level to the drive electrode driver 9. From timing t₆₉ totiming to, the amplifier COMAMP outputs the drive signals VCOM at a highlevel (reference potential Vref) to all the drive electrodes COML,thereby precharging all the drive electrodes COML at a high level(reference potential Vref).

The period from timing t₀ to timing t₇₁ corresponds to thenegative-polarity image detection period for the first horizontal lineof the second frame.

At timing to, the COG 11 causes the horizontal driver 8 to output thenegative-polarity pixel signals for the first horizontal line of thesecond frame based on the image data for the first horizontal line ofthe second frame stored in the buffer 11 a. The horizontal driver 8outputs the negative-polarity pixel signals SIG_(MINUS) for the firsthorizontal line of the second frame to one group of the two groups (thegroup of the odd-numbered signal lines SL and the group of theeven-numbered signal lines SL) of the N signal lines SL. The horizontaldriver 8 maintains the electric potential (ground potential GND) of theother group of the two groups of the N signal lines SL.

The horizontal driver 8, for example, outputs the negative-polaritypixel signals SIG_(MINUS) for the first horizontal line of the secondframe to the group of the even-numbered signal lines SL (refer to thesignal lines SL₂, SL₄, SL₆, . . . in FIG. 17) out of the N signal linesSL. The horizontal driver 8 maintains the electric potential (groundpotential GND) of the group of the odd-numbered signal lines SL (referto the signal lines SL₁, SL₃, SL₅, . . . in FIG. 17) out of the N signallines SL.

From timing t₇₀ to timing t₇₁, the COG 11 outputs the control signalSEL₃ (refer to FIG. 17) at a low level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned off. Consequently,all the drive electrodes COML are brought into a floating state fromtiming t₇₀ to timing t₇₁.

Referring back to FIG. 17, when the drive electrode COML₁ is in afloating state, the signal lines SL₂, SL₄, and SL₆ are capacitivelycoupled to the drive electrode COML₁. As a result, the detection signalis generated in the drive electrode COML₁ due to the pixel signalsSIG_(MINUS) supplied to the signal lines SL₂, SL₄, and SL₆.Subsequently, the voltage of the drive electrode COML₁ returns to avoltage corresponding to the reference potential (Vref) of theoperational amplifier included in the detection circuit of the COF 12.The COG 11 changes the control signal SEL₄ to a high level at a timingbased on the timing signal HSYNC, for example, at timing t₇₀. As aresult, the switch SW₃₁ is turned on at timing t₇₀. The detectioncircuit INT₁ reads the detection signal at timing t₇₀. The COF 12performs sampling and A/D conversion on the detection signal, therebyobtaining the negative-polarity detection pixel data. The COF 12 mayread the peak voltage of the detection signal, thereby obtaining thenegative-polarity detection pixel data.

The period from timing t₇₁ to timing t₇₂ corresponds to the displaywriting (image display) period for the first horizontal line of thesecond frame.

At timing t₇₁, the COG 11 causes the horizontal driver 8 to output thepixel signals based on the image data for the first horizontal line ofthe second frame stored in the buffer 11 a. The horizontal driver 8maintains the electric potential (negative-polarity pixel signalsSIG_(MINUS) for the first horizontal line of the second frame) of onegroup of the two groups (the group of the odd-numbered signal lines SLand the group of the even-numbered signal lines SL) of the N signallines SL. The horizontal driver 8 outputs the positive-polarity pixelsignals SIG_(PLUS) for the first horizontal line of the second frame tothe other group of the two groups of the N signal lines SL.

The horizontal driver 8, for example, maintains the electric potential(negative-polarity pixel signals SIG_(MINUS) for the first horizontalline of the second frame) of the group of the even-numbered signal linesSL (refer to the signal lines SL₂, SL₄, SL₆, . . . in FIG. 17) out ofthe N signal lines SL. The horizontal driver 8 outputs thepositive-polarity pixel signals SIG_(PLUS) for the first horizontal lineof the second frame to the group of the odd-numbered signal lines SL(refer to the signal lines SL₁, SL₃, SL₅, . . . in FIG. 17) out of the Nsignal lines SL.

From timing t₇₁ to timing t₇₂, the COG 11 outputs the control signalSEL₃ (refer to FIG. 17) at a high level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned on. The driveelectrode driver 9 outputs the drive signals VCOM at a low level(electric potential VCOMDC) to all the drive electrodes COML.Consequently, an electric field is formed between the pixel electrodesPE (refer to FIG. 3) and the drive electrodes COML, thereby displayingan image.

From timing t₇₁ to timing t₇₂, the COG 11 changes the control signalSEL₄ (refer to FIG. 17) to a low level. As a result, the switches SW₃₁and SW₃₂ are turned off, whereby neither the detection circuit INT₁ northe detection circuit INT₂ reads the drive signals VCOM at a low level(electric potential VCOMDC).

The period after timing t₇₂ corresponds to a negative-polarity imagedetection and display writing (image display) period for the secondhorizontal line of the second frame.

At timing t₇₂, the host HST outputs image data for the second horizontalline of the second frame to the COG 11. The COG 11 temporarily storesthe image data for the second horizontal line of the second framesupplied from the host HST in the buffer 11 a (refer to FIG. 2).

The period from timing t₇₂ to timing t₇₃, which is a predetermined timeafter timing t₇₂, corresponds to a precharge period for the signal linesSL and the drive electrodes COML.

From timing t₇₂ to timing t₇₃, the horizontal driver 8 outputs theground potential GND to one group of the two groups (the group of theodd-numbered signal lines SL and the group of the even-numbered signallines SL) of the N signal lines SL. The horizontal driver 8 thusprecharges the group of the odd-numbered or the even-numbered signallines SL in the N signal lines SL with the ground potential GND. Fromtiming t₇₂ to timing t₇₃, the horizontal driver 8 maintains the electricpotential (positive-polarity pixel signals SIG_(PLUS) for the firsthorizontal line of the second frame) of the other group of the twogroups of the N signal lines SL.

The horizontal driver 8, for example, outputs the ground potential GNDto the group of the even-numbered signal lines SL (refer to the signallines SL₂, SL₄, SL₆, . . . in FIG. 17) out of the N signal lines SL. Thehorizontal driver 8 maintains the electric potential (positive-polaritypixel signals SIG_(PLUS) for the first horizontal line of the secondframe) of the group of the odd-numbered signal lines SL (refer to thesignal lines SL₁, SL₃, SL₅, . . . in FIG. 17) out of the N signal linesSL.

From timing t₇₂ to timing t₇₃, the COG 11 outputs the control signalSEL₃ at a high level to the drive electrode driver 9. From timing t₇₂ totiming t₇₃, the amplifier COMAMP outputs the drive signals VCOM at ahigh level (reference potential Vref) to all the drive electrodes COML,thereby precharging all the drive electrodes COML at a high level(reference potential Vref).

The period from timing t₇₃ to timing t₇₄ corresponds to thenegative-polarity image detection period for the second horizontal lineof the second frame.

At timing t₇₃, the COG 11 causes the horizontal driver 8 to output thenegative-polarity pixel signals based on the image data for the secondhorizontal line of the second frame stored in the buffer 11 a. Thehorizontal driver 8 outputs the negative-polarity pixel signalsSIG_(MINUS) for the second horizontal line of the second frame to onegroup of the two groups (the group of the odd-numbered signal lines SLand the group of the even-numbered signal lines SL) of the N signallines SL. The horizontal driver 8 maintains the electric potential(positive-polarity pixel signals SIG_(PLUS) for the first horizontalline of the second frame) of the other group of the two groups of the Nsignal lines SL.

The horizontal driver 8, for example, outputs the negative-polaritypixel signals SIG_(MINUS) for the second horizontal line of the secondframe to the group of the even-numbered signal lines SL (refer to thesignal lines SL₂, SL₄, SL₆, . . . in FIG. 17) out of the N signal linesSL. The horizontal driver 8 maintains the electric potential(positive-polarity pixel signals SIG_(PLUS) for the first horizontalline of the second frame) of the group of the odd-numbered signal linesSL (refer to the signal lines SL₁, SL₃, SL₅, . . . in FIG. 17) out ofthe N signal lines SL.

From timing t₇₃ to timing t₇₄, the COG 11 outputs the control signalSEL₃ (refer to FIG. 17) at a low level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned off. Consequently,all the drive electrodes COML are brought into a floating state fromtiming t₇₃ to timing t₇₄.

Referring back to FIG. 17, when the drive electrode COML₁ is in afloating state, the signal lines SL₂, SL₄, and SL₆ are capacitivelycoupled to the drive electrode COML₁. As a result, the detection signalis generated in the drive electrode COML₁ due to the pixel signalsSIG_(MINUS) supplied to the signal lines SL₂, SL₄, and SL₆.Subsequently, the voltage of the drive electrode COML₁ returns to avoltage corresponding to the reference potential (Vref) of anoperational amplifier included in the detection circuit of the COF 12.The COG 11 changes the control signal SEL₄ to a high level at a timingbased on the timing signal HSYNC, for example, at timing t₇₃. As aresult, the switch SW₃₁ is turned on at timing t₇₃. The detectioncircuit INT₁ reads the detection signal at timing t₇₃. The COF 12performs sampling and A/D conversion on the detection signal, therebyobtaining the negative-polarity detection pixel data. The detectionsignal is a spike signal. The COF 12 may read the peak voltage of thedetection signal, thereby obtaining the negative-polarity detectionpixel data.

The period after timing t₇₄ corresponds to a display writing (imagedisplay) period for the second horizontal line of the second frame.

At timing t₇₄, the COG 11 causes the horizontal driver 8 to output thepixel signals based on the image data for the second horizontal line ofthe second frame stored in the buffer 11 a. The horizontal driver 8maintains the electric potential (negative-polarity pixel signalsSIG_(MINUS) for the second horizontal line of the second frame) of onegroup of the two groups (the group of the odd-numbered signal lines SLand the group of the even-numbered signal lines SL) of the N signallines SL. The horizontal driver 8 outputs the positive-polarity pixelsignals SIG_(PLUS) for the second horizontal line of the second frame tothe other group of the two groups of the N signal lines SL.

The horizontal driver 8, for example, maintains the electric potential(negative-polarity pixel signals SIG_(MINUS) for the second horizontalline of the second frame) of the group of the even-numbered signal linesSL (refer to the signal lines SL₂, SL₄, SL₆, . . . in FIG. 17) out ofthe N signal lines SL. The horizontal driver 8 outputs thepositive-polarity pixel signals SIG_(PLUS) for the second horizontalline of the second frame to the group of the odd-numbered signal linesSL (refer to the signal lines SL₁, SL₃, SL₅, . . . in FIG. 17) out ofthe N signal lines SL.

From timing t₇₄, the COG 11 outputs the control signal SEL₃ (refer toFIG. 17) at a high level to the drive electrode driver 9. As a result,the switches SW₂₁ and SW₂₂ are turned on. The drive electrode driver 9outputs the drive signals VCOM at a low level (electric potentialVCOMDC) to all the drive electrodes COML. Consequently, an electricfield is formed between the pixel electrodes PE (refer to FIG. 3) andthe drive electrodes COML, thereby displaying an image.

Similarly, the COG 11 and the COF 12 perform negative-polarity imagedetection and display writing (image display) of the third to M-thhorizontal lines of the second frame.

As described above, the number of pieces of detection pixel data in oneline of the detection image data is (N/2). As illustrated in FIG. 18,the display apparatus 1 performs image detection on a line-by-linebasis. Consequently, the detection image data includes M×(N/2) pieces ofpixel data.

Illustration and explanation of the flowchart of the exemplary operationperformed by the display apparatus according to the second embodimentare omitted because it is the same as the flowchart (refer to FIG. 13)of the second exemplary operation performed by the display apparatusaccording to the first embodiment.

Similarly to the first exemplary operation performed by the displayapparatus according to the first embodiment, the display apparatusaccording to the second embodiment can perform image detection and imagedisplay on each of the L units (refer to FIG. 6). Illustration andexplanation of the flowchart of the operation performed by the displayapparatus according to the second embodiment in this case are omittedbecause it is the same as the flowchart (refer to FIG. 10) of the firstexemplary operation performed by the display apparatus according to thefirst embodiment.

While the second embodiment describes a case where the present inventionis applied to a lateral electric field mode liquid crystal displayapparatus, the present invention is not necessarily applied thereto. Asdescribed in the first embodiment, the present invention is alsoapplicable to a vertical electric field mode liquid crystal displayapparatus.

The display apparatus according to the second embodiment has thefollowing characteristics besides the characteristics of the displayapparatus according to the first embodiment. The display apparatusaccording to the second embodiment also has characteristics other thanthose described below. The display apparatus according to the secondembodiment requires no detection line RL. Consequently, the displayapparatus according to the second embodiment can be manufactured in asimpler process at a lower cost. Furthermore, the display apparatusaccording to the second embodiment can increase the transmittance of theimage IMG (refer to FIG. 1) and improve the display quality because itrequires no detection line RL. The display apparatus may supply apositive- or negative-polarity signal to at least one signal line SL anddetect a detection signal with at least one drive electrode COMLcorresponding to the at least one signal line SL supplied with thepositive- or negative-polarity signal.

3. Third Embodiment

FIG. 19 is a diagram of the module configuration of a display apparatusaccording to a third embodiment. A panel PNLc includes a substrate 4 c,the COG 11 serving as a driver IC, and the COF 12 serving as a detectionIC. The substrate 4 c includes a first substrate 5 c and a secondsubstrate 6 c. The second substrate 6 c is disposed in the Z-directionwith respect to the first substrate 5 c and faces the first substrate 5c with a predetermined space interposed therebetween.

The substrate 4 c has the display area DA and the peripheral area GD. Inthe display area DA, a plurality of pixels Pix including liquid crystalelements are disposed in a matrix (row-column configuration). Theperipheral area GD is positioned outside the display area DA. Theperipheral area GD is provided with the vertical driver (vertical drivecircuit) 7, the horizontal driver (horizontal drive circuit) 8, and thedrive electrode driver 9.

The COG 11 is mounted on the first substrate 5 c and controls thevertical driver 7, the horizontal driver 8, and the drive electrodedriver 9. The COF 12 is mounted on the FPC T coupled to the firstsubstrate 5 c. The COG 11 and the COF 12 are coupled to the host HST(refer to FIG. 1) via the FPC T. The COG 11 includes the buffer 11 athat temporarily stores therein image data supplied from the host HST.

The display area DA has a matrix (row-column) configuration in which thepixels Pix are arrayed in M-rows and N-columns. The display area DA isprovided with the scanning lines GL and the signal lines SL. Thescanning lines GL are provided for the respective rows in the array ofM×N pixels Pix and extend in the X-direction. The signal lines SL areprovided for the respective columns and extend in the Y-direction. Inother words, the number of scanning lines GL is M, and the number ofsignal lines SL is N.

The display area DA is also provided with the drive electrodes COML. Thedrive electrodes COML are arranged one for every two rows and twocolumns of the pixels Pix. In other words, the number of driveelectrodes COML is (M/2)×(N/2). The configuration described above isgiven by way of example only, and the drive electrodes COML are notnecessarily arranged one for every two rows and two columns of thepixels Pix.

The drive electrode COML is made of a transparent material and shared bythe pixels Pix of at least one row and one column, for example. Thedrive electrodes COML are coupled to the drive electrode driver 9 viawires ML. In the image display period, the drive electrode driver 9supplies the constant drive signals VCOM to the drive electrodes COML.In the image detection period, the drive electrode driver 9 brings thedrive electrodes COML into a floating state. In the image displayperiod, the drive electrodes COML generate an electric field for drivingthe liquid crystals between the drive electrodes COML and the pixelelectrodes PE (refer to FIG. 3).

The drive electrodes COML according to the present embodiment arecapacitively coupled to the signal lines SL. The drive electrodes COMLgenerate detection signals due to the pixel signals supplied to thesignal lines SL.

The drive electrodes COML according to the present embodiment correspondto the detector DET illustrated in FIG. 1.

The COF 12 is coupled to the drive electrodes COML via the wires ML. TheCOF 12 outputs detection image data to the host HST based on thedetection signals generated in the drive electrodes COML due to thepixel signals. The drive electrodes COML according to the presentembodiment are arranged one for every two rows and two columns of thepixels Pix. In other words, the number of lines in the detection imagedata is (M/2). The number of pieces of detection pixel data in one lineof the detection image data is (N/2). In other words, the number ofelements in the detection image data is (M/2)×(N/2). The configurationdescribed above is given by way of example only, and the driveelectrodes COML are not necessarily arranged one for every two rows andtwo columns of the pixels Pix. The drive electrodes COML may be arrangedone for every one row and one column or every three or more rows andthree or more columns of the pixels Pix.

FIG. 20 is a schematic diagram of a sectional structure of a panel ofthe display apparatus according to the third embodiment. FIG. 20 is aschematic diagram of a sectional structure of one pixel Pix.

The panel PNLc is an in-cell apparatus in which the detector DET isintegrated with the display device DSP. The panel PNLc includes thefirst substrate 5 c, the second substrate 6 c, and the liquid crystalLC. The second substrate 6 c faces the first substrate 5 c. The liquidcrystal LC is disposed between the first substrate 5 c and the secondsubstrate 6 c.

The first substrate 5 c includes the substrate 31 serving as atranslucent insulation substrate. The polarization plate 32 is disposedon the surface of the substrate 31 facing in the opposite direction ofthe Z-direction. The polarization plate 32 allows only polarizationcomponents having a certain polarization direction in the light L outputfrom the light emitter BL (refer to FIG. 1) to pass therethrough.

The scanning line GL serving as a first metal layer is provided on thesurface of the substrate 31 facing in the Z-direction. The scanning lineGL extends in the X-direction (horizontal direction in FIG. 20). Aninsulation layer 33 is provided on the scanning line GL in theZ-direction. The TFT elements Tr (refer to FIG. 3), which are notillustrated in FIG. 20, may be provided between the scanning line GL andthe insulation layer 33.

Signal lines SL₁, SL₂, and SL₃ serving as a second metal layer areprovided on the insulation layer 33 in the Z-direction. The signal linesSL₁, SL₂, and SL₃ extend in the Y-direction (direction perpendicular tothe plane of FIG. 20). A planarization film 34 is provided on the signallines SL₁, SL₂, and SL₃.

Wires ML₁₋₁, ML₁₋₂, and ML₁₋₃ serving as a third metal layer areprovided in the Z-direction with respect to the signal lines SL₁, SL₂,and SL₃. Specifically, the wires ML₁₋₁, ML₁₋₂, and ML₁₋₃ are provided inthe planarization film 34. The wires ML₁₋₁, ML₁₋₂, and ML₁₋₃ extend inthe Y-direction (direction perpendicular to the plane of FIG. 20).

A drive electrode COML₁₋₁ serving as the first transparent conductivefilm layer is provided on the surface of the planarization film 34facing in the Z-direction. The drive electrode COML₁₋₁ is coupled to thewire ML₁₋₁ via a contact CON₁₋₁. The wires ML₁₋₂ and ML₁₋₃ are couplednot to the drive electrode COML₁₋₁ but to corresponding drive electrodesCOML in other rows.

The insulation film 35 is provided on the drive electrode COML₁₋₁ in theZ-direction. The pixel electrodes PE₁, PE₂, and PE₃ serving as thesecond transparent conductive film layer are provided on the surface ofthe insulation film 35 facing in the Z-direction.

Explanation of the configuration of the second substrate 6 c is omittedbecause it is the same as the configuration of the second substrate 6 baccording to the second embodiment.

FIG. 21 is a diagram of the configuration of the horizontal driver, thedrive electrode driver, and the COF of the display apparatus accordingto the third embodiment. FIG. 21 illustrates a portion of the horizontaldriver 8 that drives the pixels Pix of four columns, a portion of thedrive electrode driver 9 that drives the pixels Pix of four columns, anda portion of the COF 12 that reads detection signals of the pixels Pixof four columns.

The drive electrode COML₁₋₁ is coupled to the drive electrode driver 9and the COF 12 via the wire ML₁₋₁. A drive electrode COML₁₋₂ is coupledto the drive electrode driver 9 and the COF 12 via the wire ML₁₋₂. Adrive electrode COML₁₋₃ is coupled to the drive electrode driver 9 andthe COF 12 via the wire ML₁₋₃.

The drive electrode COML₂₋₁ is coupled to the drive electrode driver 9and the COF 12 via the wire ML₂₋₁. The drive electrode COML₂₋₂ iscoupled to the drive electrode driver 9 and the COF 12 via the wireML₂₋₂. The drive electrode COML₂₋₃ is coupled to the drive electrodedriver 9 and the COF 12 via the wire ML₂₋₃.

A switch SW₂₁₋₁ is disposed between the amplifier COMAMP and the driveelectrode COML₁₋₁. When the control signal SEL₃ supplied from the COG 11(refer to FIG. 19) is at a high level, the switch SW₂₁₋₁ electricallycouples the amplifier COMAMP to the drive electrode COML₁₋₁. When thecontrol signal SEL₃ is at a low level, the switch SW₂₁₋₁ cuts offelectrical coupling between the amplifier COMAMP and the drive electrodeCOML₁₋₁.

In the image display period, the control signal SEL₃ is at a high level.As a result, the switch SW₂₁₋₁ electrically couples the amplifier COMAMPto the drive electrode COML₁₋₁, thereby supplying the drive signal VCOMto the drive electrode COML₁₋₁. In the image detection period, thecontrol signal SEL₃ is at a low level. As a result, the switch SW₂₁₋₁cuts off electrical coupling between the amplifier COMAMP and the driveelectrode COML₁₋₁, thereby supplying no drive signal VCOM to the driveelectrode COML₁₋₁.

A switch SW₂₁₋₂ is disposed between the amplifier COMAMP and the driveelectrode COML₁₋₂. When the control signal SEL₃ supplied from the COG 11(refer to FIG. 19) is at a high level, the switch SW₂₁₋₂ electricallycouples the amplifier COMAMP to the drive electrode COML₁₋₂. When thecontrol signal SEL₃ is at a low level, the switch SW₂₁₋₂ cuts offelectrical coupling between the amplifier COMAMP and the drive electrodeCOML₁₋₂.

In the image display period, the control signal SEL₃ is at a high level.As a result, the switch SW₂₁₋₂ electrically couples the amplifier COMAMPto the drive electrode COML₁₋₂, thereby supplying the drive signal VCOMto the drive electrode COML₁₋₂. In the image detection period, thecontrol signal SEL₃ is at a low level. As a result, the switch SW₂₁₋₂cuts off electrical coupling between the amplifier COMAMP and the driveelectrode COML₁₋₂, thereby supplying no drive signal VCOM to the driveelectrode COML₁₋₂.

A switch SW₂₁₋₃ is disposed between the amplifier COMAMP and the driveelectrode COML₁₋₃. When the control signal SEL₃ supplied from the COG 11(refer to FIG. 19) is at a high level, the switch SW₂₁₋₃ electricallycouples the amplifier COMAMP to the drive electrode COML₁₋₃. When thecontrol signal SEL₃ is at a low level, the switch SW₂₁₋₃ cuts offelectrical coupling between the amplifier COMAMP and the drive electrodeCOML₁₋₃.

In the image display period, the control signal SEL₃ is at a high level.As a result, the switch SW₂₁₋₃ electrically couples the amplifier COMAMPto the drive electrode COML₁₋₃, thereby supplying the drive signal VCOMto the drive electrode COML₁₋₃. In the image detection period, thecontrol signal SEL₃ is at a low level. As a result, the switch SW₂₁₋₃cuts off electrical coupling between the amplifier COMAMP and the driveelectrode COML₁₋₃, thereby supplying no drive signal VCOM to the driveelectrode COML₁₋₃.

A switch SW₂₂₋₁ is disposed between the amplifier COMAMP and the driveelectrode COML₂₋₁. When the control signal SEL₃ supplied from the COG 11(refer to FIG. 19) is at a high level, the switch SW₂₂₋₁ electricallycouples the amplifier COMAMP to the drive electrode COML₂₋₁. When thecontrol signal SEL₃ is at a low level, the switch SW₂₂₋₁ cuts offelectrical coupling between the amplifier COMAMP and the drive electrodeCOML₂₋₁.

In the image display period, the control signal SEL₃ is at a high level.As a result, the switch SW₂₂₋₁ electrically couples the amplifier COMAMPto the drive electrode COML₂₋₁, thereby supplying the drive signal VCOMto the drive electrode COML₂₋₁. In the image detection period, thecontrol signal SEL₃ is at a low level. As a result, the switch SW₂₂₋₁cuts off electrical coupling between the amplifier COMAMP and the driveelectrode COML₂₋₁, thereby supplying no drive signal VCOM to the driveelectrode COML₂₋₁.

A switch SW₂₂₋₂ is disposed between the amplifier COMAMP and the driveelectrode COML₂₋₂. When the control signal SEL₃ supplied from the COG 11(refer to FIG. 19) is at a high level, the switch SW₂₂₋₂ electricallycouples the amplifier COMAMP to the drive electrode COML₂₋₂. When thecontrol signal SEL₃ is at a low level, the switch SW₂₂₋₂ cuts offelectrical coupling between the amplifier COMAMP and the drive electrodeCOML₂₋₂.

In the image display period, the control signal SEL₃ is at a high level.As a result, the switch SW₂₂₋₂ electrically couples the amplifier COMAMPto the drive electrode COML₂₋₂, thereby supplying the drive signal VCOMto the drive electrode COML₂₋₂. In the image detection period, thecontrol signal SEL₃ is at a low level. As a result, the switch SW₂₂₋₂cuts off electrical coupling between the amplifier COMAMP and the driveelectrode COML₂₋₂, thereby supplying no drive signal VCOM to the driveelectrode COML₂₋₂.

A switch SW₂₂₋₃ is disposed between the amplifier COMAMP and the driveelectrode COML₂₋₃. When the control signal SEL₃ supplied from the COG 11(refer to FIG. 19) is at a high level, the switch SW₂₂₋₃ electricallycouples the amplifier COMAMP to the drive electrode COML₂₋₃. When thecontrol signal SEL₃ is at a low level, the switch SW₂₂₋₃ cuts offelectrical coupling between the amplifier COMAMP and the drive electrodeCOML₂₋₃.

In the image display period, the control signal SEL₃ is at a high level.As a result, the switch SW₂₂₋₃ electrically couples the amplifier COMAMPto the drive electrode COML₂₋₃, thereby supplying the drive signal VCOMto the drive electrode COML₂₋₃. In the image detection period, thecontrol signal SEL₃ is at a low level. As a result, the switch SW₂₂₋₃cuts off electrical coupling between the amplifier COMAMP and the driveelectrode COML₂₋₃, thereby supplying no drive signal VCOM to the driveelectrode COML₂₋₃.

The drive electrodes COML according to the present embodiment arearranged one for every two rows and two columns of the pixels Pix. Inthe image display period, the drive electrodes COML₁₋₁, COML₁₋₂, andCOML₁₋₃ supply the drive signals VCOM to the pixels Pix in the first andthe second columns. Drive electrodes COML₂₋₁, COML₂₋₂, and COML₂₋₃supply the drive signals VCOM to the pixels Pix in the third and thefourth columns.

The drive electrodes COML according to the present embodiment arearranged one for every two rows and two columns of the pixels Pix. Thedrive electrodes COML₁₋₁, COML₁₋₂, and COML₁₋₃ are capacitively coupledto the signal lines SL₁ to SL₆ to generate detection signals due to thepixel signals supplied to the signal lines SL₁ to SL₆. The driveelectrodes COML₂₋₁, COML₂₋₂, and COML₂₋₃ are capacitively coupled to thesignal lines SL₇ to SL₁₂ to generate detection signals due to the pixelsignals supplied to the signal lines SL₇ to SL₁₂.

The COF 12 (refer to FIG. 19) includes detection circuits INT₁₋₁ toINT₁₋₃ and INT₂₋₁ to INT₂₋₃ serving as integration circuits. Theintegration circuits are each the detection circuit INT₁ or INT₂illustrated in FIG. 17, for example.

A switch SW₃₁₋₁ is disposed between the detection circuit INT₁₋₁ and thedrive electrode COML₁₋₁. When the control signal SEL₄ supplied from theCOG 11 (refer to FIG. 19) is at a high level, the switch SW₃₁₋₁electrically couples the detection circuit INT₁₋₁ to the drive electrodeCOML₁₋₁. When the control signal SEL₄ is at a low level, the switchSW₃₁₋₁ cuts off electrical coupling between the detection circuit INT₁₋₁and the drive electrode COML₁₋₁.

In the image display period, the control signal SEL₄ is at a low level.As a result, the switch SW₃₁₋₁ cuts off electrical coupling between thedetection circuit INT₁₋₁ and the drive electrode COML₁₋₁. In the imagedetection period, the control signal SEL₄ is at a high level. As aresult, the switch SW₃₁₋₁ electrically couples the detection circuitINT₁₋₁ to the drive electrode COML₁₋₁, thereby supplying the detectionsignal to the detection circuit INT₁₋₁. The detection circuit INT₁₋₁compares the detection signal with the reference potential Vref to readthe detection signal.

A switch SW₃₁₋₂ is disposed between the detection circuit INT₁₋₂ and thedrive electrode COML₁₋₂. When the control signal SEL₄ supplied from theCOG 11 (refer to FIG. 19) is at a high level, the switch SW₃₁₋₂electrically couples the detection circuit INT₁₋₂ to the drive electrodeCOML₁₋₂. When the control signal SEL₄ is at a low level, the switchSW₃₁₋₂ cuts off electrical coupling between the detection circuit INT₁₋₂and the drive electrode COML₁₋₂.

In the image display period, the control signal SEL₄ is at a low level.As a result, the switch SW₃₁₋₂ cuts off electrical coupling between thedetection circuit INT₁₋₂ and the drive electrode COML₁₋₂. In the imagedetection period, the control signal SEL₄ is at a high level. As aresult, the switch SW₃₁₋₂ electrically couples the detection circuitINT₁₋₂ to the drive electrode COML₁₋₂, thereby supplying the detectionsignal to the detection circuit INT₁₋₂. The detection circuit INT₁₋₂compares the detection signal with the reference potential Vref to readthe detection signal.

A switch SW₃₁₋₃ is disposed between the detection circuit INT₁₋₃ and thedrive electrode COML₁₋₃. When the control signal SEL₄ supplied from theCOG 11 (refer to FIG. 19) is at a high level, the switch SW₃₁₋₃electrically couples the detection circuit INT₁₋₃ to the drive electrodeCOML₁₋₃. When the control signal SEL₄ is at a low level, the switchSW₃₁₋₃ cuts off electrical coupling between the detection circuit INT₁₋₃and the drive electrode COML₁₋₃.

In the image display period, the control signal SEL₄ is at a low level.As a result, the switch SW₃₁₋₃ cuts off electrical coupling between thedetection circuit INT₁₋₃ and the drive electrode COML₁₋₃. In the imagedetection period, the control signal SEL₄ is at a high level. As aresult, the switch SW₃₁₋₃ electrically couples the detection circuitINT₁₋₃ to the drive electrode COML₁₋₃, thereby supplying the detectionsignal to the detection circuit INT₁₋₃. The detection circuit INT₁₋₃compares the detection signal with the reference potential Vref to readthe detection signal.

A switch SW₃₂₋₁ is disposed between the detection circuit INT₂₋₁ and thedrive electrode COML₂₋₁. When the control signal SEL₄ supplied from theCOG 11 (refer to FIG. 19) is at a high level, the switch SW₃₂₋₁electrically couples the detection circuit INT₂₋₁ to the drive electrodeCOML₂₋₁. When the control signal SEL₄ is at a low level, the switchSW₃₂₋₁ cuts off electrical coupling between the detection circuit INT₂₋₁and the drive electrode COML₂₋₁.

In the image display period, the control signal SEL₄ is at a low level.As a result, the switch SW₃₂₋₁ cuts off electrical coupling between thedetection circuit INT₂₋₁ and the drive electrode COML₂₋₁. In the imagedetection period, the control signal SEL₄ is at a high level. As aresult, the switch SW₃₂₋₁ electrically couples the detection circuitINT₂₋₁ to the drive electrode COML₂₋₁, thereby supplying the detectionsignal to the detection circuit INT₂₋₁. The detection circuit INT₂₋₁compares the detection signal with the reference potential Vref to readthe detection signal.

A switch SW₃₂₋₂ is disposed between the detection circuit INT₂₋₂ and thedrive electrode COML₂₋₂. When the control signal SEL₄ supplied from theCOG 11 (refer to FIG. 19) is at a high level, the switch SW₃₂₋₂electrically couples the detection circuit INT₂₋₂ to the drive electrodeCOML₂₋₂. When the control signal SEL₄ is at a low level, the switchSW₃₂₋₂ cuts off electrical coupling between the detection circuit INT₂₋₂and the drive electrode COML₂₋₂.

In the image display period, the control signal SEL₄ is at a low level.As a result, the switch SW₃₂₋₂ cuts off electrical coupling between thedetection circuit INT₂₋₂ and the drive electrode COML₂₋₂. In the imagedetection period, the control signal SEL₄ is at a high level. As aresult, the switch SW₃₂₋₂ electrically couples the detection circuitINT₂₋₂ to the drive electrode COML₂₋₂, thereby supplying the detectionsignal to the detection circuit INT₂₋₂. The detection circuit INT₂₋₂compares the detection signal with the reference potential Vref to readthe detection signal.

A switch SW₃₂₋₃ is disposed between the detection circuit INT₂₋₃ and thedrive electrode COML₂₋₃. When the control signal SEL₄ supplied from theCOG 11 (refer to FIG. 19) is at a high level, the switch SW₃₂₋₃electrically couples the detection circuit INT₂₋₃ to the drive electrodeCOML₂₋₃. When the control signal SEL₄ is at a low level, the switchSW₃₂₋₃ cuts off electrical coupling between the detection circuit INT₂₋₃and the drive electrode COML₂₋₃.

In the image display period, the control signal SEL₄ is at a low level.As a result, the switch SW₃₂₋₃ cuts off electrical coupling between thedetection circuit INT₂₋₃ and the drive electrode COML₂₋₃. In the imagedetection period, the control signal SEL₄ is at a high level. As aresult, the switch SW₃₂₋₃ electrically couples the detection circuitINT₂₋₃ to the drive electrode COML₂₋₃, thereby supplying the detectionsignal to the detection circuit INT₂₋₃. The detection circuit INT₂₋₃compares the detection signal with the reference potential Vref to readthe detection signal.

Illustration and explanation of the operation performed by the displayapparatus according to the third embodiment are omitted because it isthe same as the operation performed by the display apparatus accordingto the second embodiment. Similarly to the first exemplary operationperformed by the display apparatus according to the first embodiment,the display apparatus according to the third embodiment can performimage detection and image display on each of the L units (refer to FIG.6).

While the third embodiment describes a case where the present inventionis applied to a lateral electric field mode liquid crystal displayapparatus, the present invention is not necessarily applied thereto. Asdescribed in the first embodiment, the present invention is alsoapplicable to a vertical electric field mode liquid crystal displayapparatus.

The display apparatus according to the third embodiment has thefollowing characteristics besides the characteristics of the displayapparatus according to the first embodiment. The display apparatusaccording to the third embodiment also has characteristics other thanthose described below. The display apparatus according to the thirdembodiment requires no detection line RL. Consequently, the displayapparatus according to the third embodiment can be manufactured in asimpler process at a lower cost. Furthermore, the display apparatusaccording to the third embodiment can increase the transmittance of theimage IMG (refer to FIG. 1) and improve the display quality because itrequires no detection line RL. The display apparatus may supply apositive- or negative-polarity signal to at least one signal line SL anddetect a detection signal with at least one drive electrode COMLcorresponding to the at least one signal line SL supplied with thepositive- or negative-polarity signal.

4. Fourth Embodiment

FIG. 22 is a diagram of the module configuration of a display apparatusaccording to a fourth embodiment. A panel PNLd includes a substrate 4 d,the COG 11 serving as a driver IC, and the COF 12 serving as a detectionIC. The substrate 4 d includes a first substrate 5 d and a secondsubstrate 6 d. The second substrate 6 d is disposed in the Z-directionwith respect to the first substrate 5 d and faces the first substrate 5d with a predetermined space interposed therebetween.

The substrate 4 d has the display area DA and the peripheral area GD. Inthe display area DA, a plurality of pixels Pix including liquid crystalelements are disposed in a matrix (row-column configuration). Theperipheral area GD is positioned outside the display area DA. Theperipheral area GD is provided with the vertical driver (vertical drivecircuit) 7, the horizontal driver (horizontal drive circuit) 8, and thedrive electrode driver 9.

The COG 11 is mounted on the first substrate 5 d and controls thevertical driver 7, the horizontal driver 8, and the drive electrodedriver 9. The COF 12 is mounted on the FPC T coupled to the firstsubstrate 5 d. The COG 11 and the COF 12 are coupled to the host HST(refer to FIG. 1) via the FPC T. The COG 11 includes the buffer 11 athat temporarily stores therein image data supplied from the host HST.

The display area DA has a matrix (row-column) configuration in which thepixels Pix are arrayed in M-rows and N-columns. The display area DA isprovided with the scanning lines GL and the signal lines SL. Thescanning lines GL are provided for the respective rows in the array ofM×N pixels Pix and extend in the X-direction. The signal lines SL areprovided for the respective columns and extend in the Y-direction. Inother words, the number of scanning lines GL is M, and the number ofsignal lines SL is N.

The display area DA is also provided with drive electrodes COML. Thedrive electrodes COML extending in the Y-direction are arranged one forevery two columns of the pixels Pix. In other words, the number of driveelectrodes COML is (N/2). The configuration described above is given byway of example only, and the drive electrodes COML are not necessarilyarranged one for every two columns of the pixels Pix.

The drive electrode COML is made of a transparent material and shared bythe pixels Pix of at least one column, for example. The drive electrodesCOML are coupled to the drive electrode driver 9. In the image displayperiod, the drive electrode driver 9 supplies constant drive signalsVCOM to the drive electrodes COML. In the image detection period, thedrive electrode driver 9 brings the drive electrodes COML into afloating state. In the image display period, the drive electrodes COMLgenerate an electric field for driving the liquid crystals between thedrive electrodes COML and the pixel electrodes PE (refer to FIG. 3).

The wires ML are provided to the first substrate 5 d along therespective signal lines SL. Each of the wires ML is provided above thecorresponding one of the signal lines SL in the Z-direction so as tooverlap the signal line SL. While the wires ML are disposed in a layeron the signal lines SL in the Z-direction, they may be disposed in alayer under the signal lines SL.

The wires ML according to the present embodiment are capacitivelycoupled to the signal lines SL to generate detection signals due to thepixel signals supplied to the signal lines SL.

The wires ML according to the present embodiment correspond to thedetector DET illustrated in FIG. 1.

The COF 12 is coupled to the wires ML. The COF 12 outputs detectionimage data to the host HST based on the detection signals generated inthe wires ML due to the pixel signals. The wires ML according to thepresent embodiment are arranged one for every one column of the pixelsPix. In other words, the number of pieces of detection pixel data in oneline of the detection image data is N. The configuration described aboveis given by way of example only, and the wires ML are not necessarilyarranged one for every one column of the pixels Pix. The driveelectrodes COML may be arranged one for every two or more columns of thepixels Pix.

FIG. 23 is a schematic diagram of a sectional structure of a panel ofthe display apparatus according to the fourth embodiment. FIG. 23 is aschematic diagram of a sectional structure of one pixel Pix.

The panel PNLd is an in-cell apparatus in which the detector DET isintegrated with the display device DSP. The panel PNLd includes thefirst substrate 5 d, the second substrate 6 d, and the liquid crystalLC. The second substrate 6 d faces the first substrate 5 d. The liquidcrystal LC is disposed between the first substrate 5 d and the secondsubstrate 6 d.

Explanation of the configuration of the first substrate 5 d from thepolarization plate 32 to the insulation layer 33 is omitted because itis the same as the configuration of the first substrate 5 c according tothe third embodiment. The signal lines SL₁, SL₂, and SL₃ serving as thesecond metal layer are provided on the insulation layer 33 of the firstsubstrate 5 d in the Z-direction. The signal lines SL₁, SL₂, and SL₃extend in the Y-direction (direction perpendicular to the plane of FIG.23). The planarization film 34 is provided on the signal lines SL₁, SL₂,and SL₃.

Wires ML₁, ML₂, and ML₃ are provided in the Z-direction with respect tothe signal lines SL₁, SL₂, and SL₃. Specifically, the wires ML₁, ML₂,and ML₃ are provided in the planarization film 34. The wires ML₁, ML₂,and ML₃ extend in the Y-direction (direction perpendicular to the planeof FIG. 23).

The drive electrode COML₁ serving as the first transparent conductivefilm layer is provided on the surface of the planarization film 34facing in the Z-direction. The wires ML₁, ML₂, and ML₃ are not coupledto the drive electrode COML₁.

The insulation film 35 is provided on the drive electrode COML₁ in theZ-direction. The pixel electrodes PE₁, PE₂, and PE₃ serving as thesecond transparent conductive film layer are provided on the surface ofthe insulation film 35 facing in the Z-direction.

Explanation of the configuration of the second substrate 6 d is omittedbecause it is the same as the configuration of the second substrate 6 caccording to the third embodiment.

FIG. 24 is a diagram of the configuration of the horizontal driver, thedrive electrode driver, and the COF of the display apparatus accordingto the fourth embodiment. FIG. 24 illustrates a portion of thehorizontal driver 8 that drives the pixels Pix of four columns, aportion of the drive electrode driver 9 that drives the pixels Pix offour columns, and a portion of the COF 12 that reads detection signalsof the pixels Pix of four columns.

Explanation of the coupling form between the amplifier COMAMP and thedrive electrodes COML₁ and COML₂ is omitted because it is the same asthe coupling form of the second embodiment.

The wires ML according to the present embodiment are arranged one forevery one column of the pixels Pix. The wires ML₁ to ML₁₂ are coupled tothe signal lines SL₁ to SL₁₂, respectively. The wires ML₁ to ML₁₂generate detection signals due to the pixel signals supplied to thesignal lines SL₁ to SL₁₂, respectively.

The COF 12 (refer to FIG. 22) includes detection circuits INT₁ to INT₁₂serving as integration circuits. The integration circuits are each thedetection circuit INT₁ or INT₂ illustrated in FIG. 17, for example.

Switches SW₃₁ to SW₃₆ are disposed between the respective detectioncircuits INT₁ to INT₆ and the drive electrode COML₁. Switches SW₃₇ toSW₄₂ are disposed between the respective detection circuits INT₇ toINT₁₂ and the drive electrode COML₂. When the control signal SEL₄supplied from the COG 11 (refer to FIG. 22) is at a high level, each ofthe switches SW₃₁ to SW₄₂ electrically couples a corresponding one ofthe detection circuits INT₁ to INT₁₂ to a corresponding one of the driveelectrodes COML₁ and COML₂. When the control signal SEL₄ is at a lowlevel, each of the switches SW₃₁ to SW₄₂ cuts off electrical couplingbetween the corresponding one of the detection circuits INT₁ to INT₁₂and the corresponding one of the drive electrodes COML₁ and COML₂.

In the image display period, the control signal SEL₄ is at a low level.As a result, each of the switches SW₃₁ to SW₄₂ cuts off electricalcoupling between the corresponding one of the detection circuits INT₁ toINT₁₂ and the corresponding one of the drive electrodes COML₁ and COML₂.In the image detection period, the control signal SEL₄ is at a highlevel. As a result, each of the switches SW₃₁ to SW₄₂ electricallycouples the corresponding one of the detection circuits INT₁ to INT₁₂with the corresponding one of the drive electrodes COML₁ and COML₂,thereby supplying the detection signal to the corresponding one of thedetection circuits INT₁ to INT₁₂. Each of the detection circuits INT₁ toINT₁₂ compares the detection signal with the reference potential Vref toread the detection signal.

4-1. Exemplary Operation Performed by the Display Apparatus According tothe Fourth Embodiment

The following describes an exemplary operation performed by the displayapparatus according to the fourth embodiment. In the present exemplaryoperation, the display apparatus performs image display and imagedetection row by row.

FIG. 25 is a diagram of an operating timing in an exemplary operationperformed by the display apparatus according to the fourth embodiment.

The period from timing t₅₀ of the first rising edge of the timing signalTSVD to timing t₈₈ of the second rising edge of the timing signal TSVDcorresponds to the period of image display and image detection of thefirst frame. The period after timing t₈₈ of the second rising edge ofthe timing signal TSVD corresponds to the period of image display andimage detection of the second frame.

A timing signal HSYNC for detection control output from the COG 11 tothe COF 12 has the same frequency as that of the horizontalsynchronization signal for display control for displaying an image onthe display device DSP by the COG 11, for example.

During the entire period, the COG 11 outputs the control signals SEL₁and SEL₂ (refer to FIG. 24) at a high level to the horizontal driver 8.As a result, the switches SW₁ to SW₁₂ are turned on.

The period from timing t₈₁ to timing t₈₄ corresponds to apositive-polarity image detection and display writing (image display)period for the first horizontal line of the first frame.

At timing t₈₁, the host HST outputs image data for the first horizontalline of the first frame to the COG 11. The COG 11 temporarily stores theimage data for the first horizontal line of the first frame suppliedfrom the host HST in the buffer 11 a (refer to FIG. 22). The buffer 11 asimply needs to have storage capacity large enough to store thereinimage data of one horizontal line.

The period from timing t₈₁ to timing t₈₂, which is a predetermined timeafter timing t₈₁, corresponds to a precharge period for the signal linesSL.

From timing t₈₁ to timing t₈₂, the horizontal driver 8 outputs theground potential GND to all the signal lines SL, thereby precharging allthe signal lines SL with the ground potential GND. The period fromtiming t₈₂ to timing t₈₃ corresponds to the positive-polarity imagedetection period for the first horizontal line of the first frame.

At timing t₈₂, the COG 11 causes the horizontal driver 8 to output thepositive-polarity pixel signals for the first horizontal line of thefirst frame based on the image data for the first horizontal line of thefirst frame stored in the buffer 11 a. The horizontal driver 8 outputsthe positive-polarity pixel signals SIG_(PLUS) for the first horizontalline of the first frame to one group of the two groups (the group of theodd-numbered signal lines SL and the group of the even-numbered signallines SL) of the N signal lines SL. The horizontal driver 8 maintainsthe electric potential (ground potential GND) of the other group of thetwo groups of the N signal lines SL.

The horizontal driver 8, for example, outputs the positive-polaritypixel signals SIG_(PLUS) for the first horizontal line of the firstframe to the group of the odd-numbered signal lines SL (refer to thesignal lines SL₁, SL₃, SL₅, . . . in FIG. 24) out of the N signal linesSL. The horizontal driver 8 maintains the electric potential (groundpotential GND) of the group of the even-numbered signal lines SL (referto the signal lines SL₂, SL₄, SL₆, . . . in FIG. 24) out of the N signallines SL.

From timing t₈₁ to timing t₈₃, the COG 11 outputs the control signalSEL₃ (refer to FIG. 24) at a low level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned off. Consequently,all the drive electrodes COML are brought into a floating state.

Referring back to FIG. 24, the signal lines SL₁ to SL₁₂ are capacitivelycoupled to the wires ML₁ to ML₁₂, respectively. As a result, detectionsignals SIG_(ML) are generated in the wires ML₁, ML₃, ML₅, ML₇, ML₉, andML₁₁ due to the pixel signals SIG_(PLUS) supplied to the signal linesSL₁, SL₃, SL₅, SL₇, SL₉, and SL₁₁ respectively. The COG 11 changes thecontrol signal SEL₄ to a high level at a timing based on the timingsignal HSYNC, for example, at timing t₈₂. As a result, the switches SW₃₁to SW₄₂ are turned on at timing t₈₂. The detection circuits INT₁, INT₃,INT₅, INT₇, INT₉ and INT₁₁ read the corresponding detection signalsSIG_(ML) at timing t₈₂. The COF 12 performs sampling and A/D conversionon the detection signals SIG_(ML), thereby obtaining thepositive-polarity detection pixel data. The detection signal SIG_(ML) isa spike signal. The COF 12 may read the peak voltage of the detectionsignals SIG_(ML), thereby obtaining the positive-polarity detectionpixel data.

The period from timing t₈₃ to timing t₈₄ corresponds to the displaywriting (image display) period for the first horizontal line of thefirst frame.

At timing t₈₃, the COG 11 causes the horizontal driver 8 to output thepixel signals based on the image data for the first horizontal line ofthe first frame stored in the buffer 11 a. The horizontal driver 8maintains the electric potential (positive-polarity pixel signalsSIG_(PLUS) for the first horizontal line of the first frame) of onegroup of the two groups (the group of the odd-numbered signal lines SLand the group of the even-numbered signal lines SL) of the N signallines SL. The horizontal driver 8 outputs the negative-polarity pixelsignals SIG_(MINUS) for the first horizontal line of the first frame tothe other group of the two groups of the N signal lines SL.

The horizontal driver 8, for example, maintains the electric potential(positive-polarity pixel signals SIG_(PLUS) for the first horizontalline of the first frame) of the group of the odd-numbered signal linesSL (refer to the signal lines SL₁, SL₃, SL₅, . . . in FIG. 24) out ofthe N signal lines SL. The horizontal driver 8 outputs thenegative-polarity pixel signals SIG_(MINUS) for the first horizontalline of the first frame to the group of the even-numbered signal linesSL (refer to the signal lines SL₂, SL₄, SL₆, . . . in FIG. 24) out ofthe N signal lines SL.

From timing t₈₃ to timing t₈₄, the COG 11 outputs the control signalSEL₃ (refer to FIG. 24) at a high level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned on. The driveelectrode driver 9 outputs the drive signals VCOM to all the driveelectrodes COML. Consequently, an electric field is formed between thepixel electrodes PE (refer to FIG. 3) and the drive electrodes COML,thereby displaying an image.

From timing t₈₃ to timing t₈₄, the COG 11 changes the control signalSEL₄ (refer to FIG. 24) to a low level. As a result, the switches SW₃₁to SW₄₂ are turned off, whereby the detection circuits INT₁ to INT₁₂ donot read the detection signals SIG_(ML).

The period from timing t₈₄ to timing t₈₇ corresponds to apositive-polarity image detection and display writing (image display)period for the second horizontal line of the first frame.

At timing t₈₄, the host HST outputs image data for the second horizontalline of the first frame to the COG 11. The COG 11 temporarily stores theimage data for the second horizontal line of the first frame suppliedfrom the host HST in the buffer 11 a (refer to FIG. 22).

The period from timing t₈₄ to timing t₈₅, which is a predetermined timeafter timing t₈₄, corresponds to a precharge period for the signal linesSL.

From timing t₈₄ to timing t₈₅, the horizontal driver 8 outputs theground potential GND to one group of the two groups (the group of theodd-numbered signal lines SL and the group of the even-numbered signallines SL) of the N signal lines SL. The horizontal driver 8 thusprecharges the group of the odd-numbered or the even-numbered signallines SL in the N signal lines SL with the ground potential GND. Fromtiming t₈₄ to timing t₈₅, the horizontal driver 8 maintains the electricpotential (negative-polarity pixel signals SIG_(MINUS) for the firsthorizontal line of the first frame) of the other group of the two groupsof the N signal lines SL.

The horizontal driver 8, for example, outputs the ground potential GNDto the group of the odd-numbered signal lines SL (refer to the signallines SL₁, SL₃, SL₅, . . . in FIG. 24) out of the N signal lines SL. Thehorizontal driver 8 maintains the electric potential (negative-polaritypixel signals SIG_(MINUS) for the first horizontal line of the firstframe) of the group of the even-numbered signal lines SL (refer to thesignal lines SL₂, SL₄, SL₆, . . . in FIG. 24) out of the N signal linesSL.

The period from timing t₈₅ to timing t₈₆ corresponds to thepositive-polarity image detection period for the second horizontal lineof the first frame.

At timing t₈₅, the COG 11 causes the horizontal driver 8 to output thepositive-polarity pixel signals based on the image data for the secondhorizontal line of the first frame stored in the buffer 11 a. Thehorizontal driver 8 outputs the positive-polarity pixel signalsSIG_(PLUS) for the second horizontal line of the first frame to onegroup of the two groups (the group of the odd-numbered signal lines SLand the group of the even-numbered signal lines SL) of the N signallines SL. The horizontal driver 8 maintains the electric potential(negative-polarity pixel signals SIG_(MINUS) for the first horizontalline of the first frame) of the other group of the two groups of the Nsignal lines SL.

The horizontal driver 8, for example, outputs the positive-polaritypixel signals SIG_(PLUS) for the second horizontal line of the firstframe to the group of the odd-numbered signal lines SL (refer to thesignal lines SL₁, SL₃, SL₅, . . . in FIG. 24) out of the N signal linesSL. The horizontal driver 8 maintains the electric potential(negative-polarity pixel signals SIG_(MINUS) for the first horizontalline of the first frame) of the group of the even-numbered signal linesSL (refer to the signal lines SL₂, SL₄, SL₆, . . . in FIG. 24) out ofthe N signal lines SL.

From timing t₈₅ to timing t₈₆, the COG 11 outputs the control signalSEL₃ (refer to FIG. 24) at a low level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned off. Consequently,all the drive electrodes COML are brought into a floating state.

Referring back to FIG. 24, the signal lines SL₁ to SL₁₂ are capacitivelycoupled to the wires ML₁ to ML₁₂, respectively. As a result, detectionsignals SIG_(ML) are generated in the wires ML₁, ML₃, ML₅, ML₇, ML₉, andML₁₁ due to the pixel signals SIG_(PLUS) supplied to the signal linesSL₁, SL₃, SL₅, SL₇, SL₉, and SL₁₁ respectively. The COG 11 changes thecontrol signal SEL₄ to a high level at a timing based on the timingsignal HSYNC, for example, at timing t₈₅. As a result, the switches SW₃₁to SW₄₂ are turned on at timing t₈₅. The detection circuits INT₁, INT₃,INT₅, INT₇, INT₉ and INT₁₁ read the detection signals SIG_(ML) at timingt₈₅. The COF 12 performs sampling and A/D conversion on the detectionsignals SIG_(ML), thereby obtaining the positive-polarity detectionpixel data. The COF 12 may read the peak voltage of the detectionsignals SIG_(ML), thereby obtaining the positive-polarity detectionpixel data.

The period from timing t₈₆ to timing t₈₇ corresponds to the displaywriting (image display) period for the second horizontal line of thefirst frame.

At timing t₈₆, the COG 11 causes the horizontal driver 8 to output thepixel signals based on the image data for the second horizontal line ofthe first frame stored in the buffer 11 a. The horizontal driver 8maintains the electric potential (positive-polarity pixel signalsSIG_(PLUS) for the second horizontal line of the first frame) of onegroup of the two groups (the group of the odd-numbered signal lines SLand the group of the even-numbered signal lines SL) of the N signallines SL. The horizontal driver 8 outputs the negative-polarity pixelsignals SIG_(MINUS) for the second horizontal line of the first frame tothe other group of the two groups of the N signal lines SL.

The horizontal driver 8, for example, maintains the electric potential(positive-polarity pixel signals SIG_(PLUS) for the second horizontalline of the first frame) of the group of the odd-numbered signal linesSL (refer to the signal lines SL₁, SL₃, SL₅, . . . in FIG. 24) out ofthe N signal lines SL. The horizontal driver 8 outputs thenegative-polarity pixel signals SIG_(MINUS) for the second horizontalline of the first frame to the group of the even-numbered signal linesSL (refer to the signal lines SL₂, SL₄, SL₆, . . . in FIG. 24) out ofthe N signal lines SL.

From timing t₈₆ to timing t₈₇, the COG 11 outputs the control signalSEL₃ (refer to FIG. 24) at a high level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned on. The driveelectrode driver 9 outputs the drive signals VCOM to all the driveelectrodes COML. Consequently, an electric field is formed between thepixel electrodes PE (refer to FIG. 3) and the drive electrodes COML,thereby displaying an image.

From timing t₈₆ to timing t₈₇, the COG 11 changes the control signalSEL₄ (refer to FIG. 24) to a low level. As a result, the switches SW₃₁to SW₄₂ are turned off, whereby the detection circuits INT₁ to INT₁₂ donot read the detection signals SIG_(ML).

Similarly, the COG 11 and the COF 12 perform positive-polarity imagedetection and display writing (image display) of the third to M-thhorizontal lines of the first frame.

The period from timing t₈₉ to timing t₉₂ corresponds to anegative-polarity image detection and display writing (image display)period for the first horizontal line of the second frame.

At timing t₈₉, the host HST outputs image data for the first horizontalline of the second frame to the COG 11. The COG 11 temporarily storesthe image data for the first horizontal line of the second framesupplied from the host HST in the buffer 11 a (refer to FIG. 22). Thebuffer 11 a simply needs to have storage capacity large enough to storetherein image data of one horizontal line.

The period from timing t₈₉ to timing t₉₀, which is a predetermined timeafter timing t₈₉, corresponds to a precharge period for the signal linesSL.

From timing t₈₉ to timing t₉₀, the horizontal driver 8 outputs theground potential GND to all the signal lines SL, thereby precharging allthe signal lines SL with the ground potential GND.

The period from timing t₉₀ to timing t₉₁ corresponds to thenegative-polarity image detection period for the first horizontal lineof the second frame.

At timing t₉₀, the COG 11 causes the horizontal driver 8 to output thenegative-polarity pixel signals for the first horizontal line of thesecond frame based on the image data for the first horizontal line ofthe second frame stored in the buffer 11 a. The horizontal driver 8outputs the negative-polarity pixel signals SIG_(MINUS) for the firsthorizontal line of the second frame to one group of the two groups (thegroup of the odd-numbered signal lines SL and the group of theeven-numbered signal lines SL) of the N signal lines SL. The horizontaldriver 8 maintains the electric potential (ground potential GND) of theother group of the two groups of the N signal lines SL.

The horizontal driver 8, for example, outputs the negative-polaritypixel signals SIG_(MINUS) for the first horizontal line of the secondframe to the group of the even-numbered signal lines SL (refer to thesignal lines SL₂, SL₄, SL₆, . . . in FIG. 24) out of the N signal linesSL. The horizontal driver 8 maintains the electric potential (groundpotential GND) of the group of the odd-numbered signal lines SL (referto the signal lines SL₁, SL₃, SL₅, . . . in FIG. 24) out of the N signallines SL.

From timing t₉₀ to timing t₉₁, the COG 11 outputs the control signalSEL₃ (refer to FIG. 24) at a low level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned off. Consequently,all the drive electrodes COML are brought into a floating state.

Referring back to FIG. 24, the signal lines SL₁ to SL₁₂ are capacitivelycoupled to the wires ML₁ to ML₁₂, respectively. As a result, thedetection signals SIG_(ML) are generated in the wires ML₂, ML₄, ML₆,ML₈, ML₁₀, and ML₁₂ due to the pixel signals SIG_(MINUS) supplied to thesignal lines SL₂, SL₄, SL₆, SL₈, SL₁₀, and SL₁₂ respectively. The COG 11changes the control signal SEL₄ to a high level at a timing based on thetiming signal HSYNC, for example, at timing t₉₀. As a result, theswitches SW₃₁ to SW₄₂ are turned on at timing t₉₀. The detectioncircuits INT₂, INT₄, INT₆, INT₈, INT₁₀ and INT₁₂ read the detectionsignals SIG_(ML) at timing t₉₀. The COF 12 performs sampling and A/Dconversion on the detection signals SIG_(ML), thereby obtaining thenegative-polarity detection pixel data. The COF 12 may read the peakvoltage of the detection signals SIG_(ML), thereby obtaining thenegative-polarity detection pixel data.

The period from timing t₉₁ to timing t₉₂ corresponds to the displaywriting (image display) period for the first horizontal line of thesecond frame.

At timing t₉₁, the COG 11 causes the horizontal driver 8 to output thepixel signals based on the image data for the first horizontal line ofthe second frame stored in the buffer 11 a. The horizontal driver 8maintains the electric potential (negative-polarity pixel signalsSIG_(MINUS) for the first horizontal line of the second frame) of onegroup of the two groups (the group of the odd-numbered signal lines SLand the group of the even-numbered signal lines SL) of the N signallines SL. The horizontal driver 8 outputs the positive-polarity pixelsignals SIG_(PLUS) for the first horizontal line of the second frame tothe other group of the two groups of the N signal lines SL.

The horizontal driver 8, for example, maintains the electric potential(negative-polarity pixel signals SIG_(MINUS) for the first horizontalline of the second frame) of the group of the even-numbered signal linesSL (refer to the signal lines SL₂, SL₄, SL₆, . . . in FIG. 24) out ofthe N signal lines SL. The horizontal driver 8 outputs thepositive-polarity pixel signals SIG_(PLUS) for the first horizontal lineof the second frame to the group of the odd-numbered signal lines SL(refer to the signal lines SL₁, SL₃, SL₅, . . . in FIG. 24) out of the Nsignal lines SL.

From timing t₉₁ to timing t₉₂, the COG 11 outputs the control signalSEL₃ (refer to FIG. 24) at a high level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned on. The driveelectrode driver 9 outputs the drive signals VCOM to all the driveelectrodes COML. Consequently, an electric field is formed between thepixel electrodes PE (refer to FIG. 3) and the drive electrodes COML,thereby displaying an image.

The period after timing t₉₂ corresponds to a negative-polarity imagedetection and display writing (image display) period for the secondhorizontal line of the second frame.

At timing t₉₂, the host HST outputs image data for the second horizontalline of the second frame to the COG 11. The COG 11 temporarily storesthe image data for the second horizontal line of the second framesupplied from the host HST in the buffer 11 a (refer to FIG. 22).

The period from timing t₉₂ to timing t₉₃, which is a predetermined timeafter timing t₉₂, corresponds to a precharge period for the signal linesSL.

From timing t₉₂ to timing t₉₃, the horizontal driver 8 outputs theground potential GND to one group of the two groups (the group of theodd-numbered signal lines SL and the group of the even-numbered signallines SL) of the N signal lines SL. The horizontal driver 8 thusprecharges the group of the odd-numbered or the even-numbered signallines SL in the N signal lines SL with the ground potential GND. Fromtiming t₉₂ to timing t₉₃, the horizontal driver 8 maintains the electricpotential (positive-polarity pixel signals SIG_(PLUS) for the firsthorizontal line of the second frame) of the other group of the twogroups of the N signal lines SL.

The horizontal driver 8, for example, outputs the ground potential GNDto the group of the even-numbered signal lines SL (refer to the signallines SL₂, SL₄, SL₆, . . . in FIG. 24) out of the N signal lines SL. Thehorizontal driver 8 maintains the electric potential (positive-polaritypixel signals SIG_(PLUS) for the first horizontal line of the secondframe) of the group of the odd-numbered signal lines SL (refer to thesignal lines SL₁, SL₃, SL₅, . . . in FIG. 24) out of the N signal linesSL.

The period from timing t₉₃ to timing t₉₄ corresponds to thenegative-polarity image detection period for the second horizontal lineof the second frame.

At timing t₉₃, the COG 11 causes the horizontal driver 8 to output thenegative-polarity pixel signals based on the image data for the secondhorizontal line of the second frame stored in the buffer 11 a. Thehorizontal driver 8 outputs the negative-polarity pixel signalsSIG_(MINUS) for the second horizontal line of the second frame to onegroup of the two groups (the group of the odd-numbered signal lines SLand the group of the even-numbered signal lines SL) of the N signallines SL. The horizontal driver 8 maintains the electric potential(positive-polarity pixel signals SIG_(PLUS) for the first horizontalline of the second frame) of the other group of the two groups of the Nsignal lines SL.

The horizontal driver 8, for example, outputs the negative-polaritypixel signals SIG_(MINUS) for the second horizontal line of the secondframe to the group of the even-numbered signal lines SL (refer to thesignal lines SL₂, SL₄, SL₆, . . . in FIG. 24) out of the N signal linesSL. The horizontal driver 8 maintains the electric potential(positive-polarity pixel signals SIG_(PLUS) for the first horizontalline of the second frame) of the group of the odd-numbered signal linesSL (refer to the signal lines SL₁, SL₃, SL₅, . . . in FIG. 24) out ofthe N signal lines SL.

From timing t₉₃ to timing t₉₄, the COG 11 outputs the control signalSEL₃ (refer to FIG. 24) at a low level to the drive electrode driver 9.As a result, the switches SW₂₁ and SW₂₂ are turned off. Consequently,all the drive electrodes COML are brought into a floating state.

Referring back to FIG. 24, the signal lines SL₁ to SL₁₂ are capacitivelycoupled to the wires ML₁ to ML₁₂, respectively. As a result, thedetection signals SIG_(ML) are generated in the wires ML₂, ML₄, ML₆,ML₈, ML₁₀, and ML₁₂ due to the pixel signals SIG_(MINUS) supplied to thesignal lines SL₂, SL₄, SL₆, SL₈, SL₁₀, and SL₁₂ respectively. The COG 11changes the control signal SEL₄ to a high level at a timing based on thetiming signal HSYNC, for example, at timing t₉₃. As a result, theswitches SW₃₁ to SW₄₂ are turned on at timing t₉₃. The detectioncircuits INT₂, INT₄, INT₆, INT₈, INT₁₀ and INT₁₂ read the detectionsignals SIG_(ML) at timing t₉₃. The COF 12 performs sampling and A/Dconversion on the detection signals SIG_(ML), thereby obtaining thenegative-polarity detection pixel data. The COF 12 may read the peakvoltage of the detection signals SIG_(ML), thereby obtaining thenegative-polarity detection pixel data.

The period after timing t₉₄ corresponds to a display writing (imagedisplay) period for the second horizontal line of the second frame.

At timing t₉₄, the COG 11 causes the horizontal driver 8 to output thepixel signals based on the image data for the second horizontal line ofthe second frame stored in the buffer 11 a. The horizontal driver 8maintains the electric potential (negative-polarity pixel signalsSIG_(MINUS) for the second horizontal line of the second frame) of onegroup of the two groups (the group of the odd-numbered signal lines SLand the group of the even-numbered signal lines SL) of the N signallines SL. The horizontal driver 8 outputs the positive-polarity pixelsignals SIG_(PLUS) for the second horizontal line of the second frame tothe other group of the two groups of the N signal lines SL.

The horizontal driver 8, for example, maintains the electric potential(negative-polarity pixel signals SIG_(MINUS) for the second horizontalline of the second frame) of the group of the even-numbered signal linesSL (refer to the signal lines SL₂, SL₄, SL₆, . . . in FIG. 24) out ofthe N signal lines SL. The horizontal driver 8 outputs thepositive-polarity pixel signals SIG_(PLUS) for the second horizontalline of the second frame to the group of the odd-numbered signal linesSL (refer to the signal lines SL₁, SL₃, SL₅, . . . in FIG. 24) out ofthe N signal lines SL.

From timing t₉₄, the COG 11 outputs the control signal SEL₃ (refer toFIG. 24) at a high level to the drive electrode driver 9. As a result,the switches SW₂₁ and SW₂₂ are turned on. The drive electrode driver 9outputs the drive signals VCOM at a low level (electric potentialVCOMDC) to all the drive electrodes COML. Consequently, an electricfield is formed between the pixel electrodes PE (refer to FIG. 3) andthe drive electrodes COML, thereby displaying an image.

Similarly, the COG 11 and the COF 12 perform negative-polarity imagedetection and display writing (image display) of the third to M-thhorizontal lines of the second frame.

As described above, the number of pieces of detection pixel data in oneline of the detection image data is N. As illustrated in FIG. 25, thedisplay apparatus 1 performs image detection on a line-by-line basis.Consequently, the detection image data includes M×N pieces of pixeldata.

Illustration and explanation of the flowchart of the exemplary operationperformed by the display apparatus according to the fourth embodimentare omitted because it is the same as the flowchart (refer to FIG. 13)of the second exemplary operation performed by the display apparatusaccording to the first embodiment.

Similarly to the first exemplary operation performed by the displayapparatus according to the first embodiment, the display apparatusaccording to the fourth embodiment can perform image detection and imagedisplay on each of the L units (refer to FIG. 6). Illustration andexplanation of the flowchart of the operation performed by the displayapparatus according to the fourth embodiment in this case are omittedbecause it is the same as the flowchart (refer to FIG. 10) of the firstexemplary operation performed by the display apparatus according to thefirst embodiment.

While the fourth embodiment describes a case where the present inventionis applied to a lateral electric field mode liquid crystal displayapparatus, the present invention is not necessarily applied thereto. Thepresent invention is also applicable to a vertical electric field modeliquid crystal display apparatus.

FIG. 26 is a schematic diagram of a sectional structure of a panel ofthe display apparatus according to a modification of the fourthembodiment. FIG. 26 is a schematic diagram of a sectional structure ofthree pixels Pix.

A panel PNLe is an in-cell apparatus in which the detector DET isintegrated with the display device DSP.

The panel PNLe includes a first substrate 5 e, a second substrate 6 e,and the liquid crystal LC. The second substrate 6 e faces the firstsubstrate 5 e. The liquid crystal LC is disposed between the firstsubstrate 5 e and the second substrate 6 e.

The first substrate 5 e includes the substrate 31 serving as atranslucent insulation substrate. The polarization plate 32 is disposedon the surface of the substrate 31 facing in the Z-direction.

The scanning line GL serving as a first metal layer is provided on thesurface of the substrate 31 facing in the Z-direction. The scanning lineGL extends in the X-direction (horizontal direction in FIG. 26). Aninsulation layer 33 is provided on the scanning line GL in theZ-direction. The TFT elements Tr (refer to FIG. 3), which are notillustrated in FIG. 26, may be provided between the scanning line GL andthe insulation layer 33.

The signal lines SL₁ to SL₉ serving as the second metal layer areprovided on the surface of the insulation layer 33 facing in theZ-direction. The signal lines SL₁ to SL₉ extend in the Y-direction(direction perpendicular to the plane of FIG. 26). An insulation layer36 is provided in the Z-direction with respect to the insulation layer33 and the signal lines SL₁ to SL₉.

The wires ML₁ to ML₉ serving as the third metal layer are provided on asurface of the insulation layer 36 facing in the Z-direction. The wiresML₁ to ML₉ are provided in the Z-direction with respect to the signallines SL₁ to SL₉. The wires ML₁ to ML₉ extend in the Y-direction(direction perpendicular to the plane of FIG. 26). An insulation layer37 is provided in the Z-direction with respect to the insulation layer36 and the wires ML₁ to ML₉.

The pixel electrodes PE₁ to PE₉ serving as the transparent conductivefilm layer are provided on a surface of the insulation layer 37 facingin the Z-direction.

The configuration of the second substrate 6 e is different from that ofthe second substrate 6 a (refer to FIG. 14) according to themodification of the first embodiment in that no detection line RL isprovided.

An electric field is formed between each of the pixel electrodes PE₁,PE₂, and PE₃ and the drive electrode COML₁. The electric field causesthe molecules of the liquid crystal LC to rise and fall along theZ-direction, thereby rotating the polarization direction of light havingpassed through the polarization plate 32. An electric field is formedbetween each of the pixel electrodes PE₄, PE₅, and PE₆ and the driveelectrode COML₂. The electric field causes the molecules of the liquidcrystal LC to rise and fall along the Z-direction, thereby rotating thepolarization direction of light having passed through the polarizationplate 32. An electric field is formed between each of the pixelelectrodes PE₇, PE₈, and PE₉ and the drive electrode COML₃. The electricfield causes the molecules of the liquid crystal LC to rise and fallalong the Z-direction, thereby rotating the polarization direction oflight having passed through the polarization plate 32. In other words,the panel PNLe is a vertical electric field mode liquid crystal displayapparatus.

The display apparatus according to the fourth embodiment has thefollowing characteristics besides the characteristics of the displayapparatus according to the first embodiment. The display apparatusaccording to the fourth embodiment also has characteristics other thanthose described below. The display apparatus according to the fourthembodiment requires no detection line RL. Consequently, the displayapparatus according to the fourth embodiment can increase thetransmittance of the image IMG (refer to FIG. 1) and improve the displayquality. The display apparatus may supply a positive- ornegative-polarity signal to at least one signal line SL and detect adetection signal with at least one wire ML corresponding to the at leastone signal line SL supplied with the positive- or negative-polaritysignal.

5. Fifth Embodiment

FIG. 27 is a block diagram of the configuration of a display apparatusaccording to a fifth embodiment.

A display apparatus if according to the present embodiment includes apanel PNLf, the light emitter BL, the detector DET, and the controllerCTL. The panel PNLf includes the display device DSP that displays animage.

The light emitter BL is disposed in the opposite direction of theZ-direction with respect to the panel PNLf. The light emitter BL outputsthe light L in the Z-direction to irradiate the panel PNLf.

The display device DSP receives the light L output from the lightemitter BL to display an image IMG in the Z-direction.

The detector DET electrically detects the image IMG displayed by thedisplay device DSP. Specifically, the detector DET includes detectionlines capacitively coupled to signal lines that supply pixel signals topixels in the display device DSP. The detector DET generates detectionsignals in the detection lines due to the pixel signals.

The display apparatus if according to the present embodiment has theimage display period for displaying an image and the image detectionperiod for detecting an image. The display apparatus if according to thepresent embodiment employs a column inversion driving method ofinverting the polarity of image signals alternately in columns (pixelcolumns) adjacent to each other, which will be described later. Theimage detection period includes a period for detecting apositive-polarity image and a period for detecting a negative-polarityimage.

The light emitter BL and the detector DET may be integrated.Alternatively, the detector DET may be attached to the light emitter BL.

The following describes a specific exemplary configuration of the lightemitter BL and the detector DET. The exemplary configuration below isgiven by way of example only, and the present invention is not limitedthereto.

FIG. 28 is a diagram of the module configuration of the displayapparatus according to the fifth embodiment. The panel PNLf is differentfrom the panel PNL (refer to FIG. 2) of the display apparatus accordingto the first embodiment in that neither the COF 12 nor the detectionline RL is provided.

FIG. 29 is a diagram of the configuration of the light emitter of thedisplay apparatus according to the fifth embodiment. The light emitterBL is disposed on a back surface side (a side facing in the oppositedirection of the Z-direction) of the panel PNLf. In FIG. 29, the displayarea DA, the pixels Pix, the scanning lines GL, the signal lines SL, andthe drive electrodes COML, which are the components included in thepanel PNLf, are indicated by the dotted lines.

On the back surface side (the side facing in the opposite direction ofthe Z-direction) of the light emitter BL, the detection lines RLextending in the Y-direction are arranged one for every two columns ofthe pixels Pix such that the detection lines RL correspond to therespective drive electrodes COML. In other words, the number ofdetection lines RL is (N/2). The configuration described above is givenby way of example only, and the detection lines RL are not necessarilyarranged one for every two columns of the pixels Pix.

The COF 12 on the FPC T is coupled to the detection lines RL. The COF 12outputs detection image data to the host HST based on the detectionsignals generated in the detection lines RL due to the pixel signals.The detection lines RL according to the present embodiment are arrangedone for every two columns of the pixels Pix. The number of pieces ofdetection pixel data in one line of the detection image data is (N/2).The configuration described above is given by way of example only, andthe detection lines RL are not necessarily arranged one for every twocolumns of the pixels Pix. The detection lines RL may be arranged onefor every one or every three or more columns of the pixels Pix.

FIG. 30 is a schematic diagram of a first example of a sectionalstructure of the display apparatus according to the fifth embodiment.FIG. 30 is a schematic diagram of a sectional structure of one pixelPix.

The panel PNLf includes a first substrate 5 f, a second substrate 6 f,and the liquid crystal LC. The second substrate 6 f faces the firstsubstrate 5 f. The liquid crystal LC is disposed between the firstsubstrate 5 f and the second substrate 6 f The configuration of thefirst substrate 5 f is the same as that of the first substrate 5 (referto FIG. 4) of the display apparatus according to the first embodiment.

The configuration of the second substrate 6 f is different from that ofthe second substrate 6 (refer to FIG. 4) according to the firstembodiment in that no detection line RL is provided.

The light emitter BL is provided in the opposite direction of theZ-direction with respect to the first substrate 5 f. The detection lineRL is provided in the Z-direction with respect to the light emitter BL.In other words, the detection line RL is provided between thepolarization plate 32 and the light emitter BL. The detection line RLextends in the Y-direction (direction perpendicular to the plane of FIG.30).

FIG. 31 is a schematic diagram of a second example of a sectionalstructure of the display apparatus according to the fifth embodiment.FIG. 31 is a schematic diagram of a sectional structure of one pixelPix.

The light emitter BL is provided in the opposite direction of theZ-direction with respect to the first substrate 5 f. The detection lineRL is provided in the opposite direction of the Z-direction with respectto the light emitter BL. The detection line RL extends in theY-direction (direction perpendicular to the plane of FIG. 31).

FIG. 32 is a schematic diagram of a third example of a sectionalstructure of the display apparatus according to the fifth embodiment.FIG. 32 is a schematic diagram of a sectional structure of one pixelPix.

The light emitter BL is provided in the opposite direction of theZ-direction with respect to the first substrate 5 f. The detection lineRL is provided in the light emitter BL. The detection line RL extends inthe Y-direction (direction perpendicular to the plane of FIG. 32).

FIG. 33 is a schematic diagram of a first example of a sectionalstructure of the light emitter in the display apparatus according to thefifth embodiment. The light emitter BL illustrated in FIG. 33corresponds to that in the first example of the sectional structure ofthe display apparatus if illustrated in FIG. 30.

The light emitter BL includes a light guide plate 61 and a light source66. The light source 66 is provided on the opposite side in theX-direction of the light guide plate 61. The light source 66 outputslight Lo in the X-direction. The light Lo travels in the X-direction andenters into the light guide plate 61 from its side surface. The lightguide plate 61 guides the entering light Lo toward the panel PNLf, thatis, in the Z-direction.

A reflective plate 62 is provided on a surface of the light guide plate61 facing in the opposite direction of the Z-direction. The reflectiveplate 62 reflects, in the Z-direction, light output from the light guideplate 61 and traveling in the opposite direction of the Z-direction.With this mechanism, the reflective plate 62 can effectively direct thelight Lo, which is output from the light source 66, toward the panelPNLf.

A diffusion film 63 is provided on a surface of the light guide plate 61facing in the Z-direction. The diffusion film 63 diffuses the lightoutput from the light guide plate 61 toward the panel PNLf, that is, inthe Z-direction across the entire panel PNLf. The diffusion film 63 thuscan equalize the luminance of the panel PNLf.

A first luminance enhancement film 64 is provided on a surface of thediffusion film 63 facing in the Z-direction. The first luminanceenhancement film 64 is produced by uniformly and precisely forming anacrylic resin prism pattern on a surface of a translucent polyester, forexample. The first luminance enhancement film 64 condenses the lightoutput from the diffusion film 63 and traveling in the Z-directiontoward a user of the display apparatus 1 f, thereby increasing the frontluminance. The first luminance enhancement film 64 can reflect unusedlight outside the viewing angle into the viewing angle again, therebycondensing the light at a suitable angle in the direction toward theuser of the display apparatus 1 f.

The detection line RL is provided on a surface of the first luminanceenhancement film 64 facing in the Z-direction. The detection line RLextends in the Y-direction (direction perpendicular to the plane of FIG.33).

A second luminance enhancement film 65 is provided on a surface of thedetection line RL facing in the Z-direction. The second luminanceenhancement film 65 is a reflective polarization film having amultilayered thin film structure, for example. The second luminanceenhancement film 65 can brighten the screen of the panel PNLf withoutallowing the light output from the first luminance enhancement film 64to be absorbed into the polarization plate 32 (refer to FIG. 31) of thepanel PNLf.

FIG. 34 is a schematic diagram of a second example of a sectionalstructure of the light emitter in the display apparatus according to thefifth embodiment. The light emitter BL illustrated in FIG. 34corresponds to that in the first example of the sectional structure ofthe display apparatus if illustrated in FIG. 30.

The detection line RL is provided on the surface of the diffusion film63 facing in the Z-direction. The detection line RL extends in theY-direction (direction perpendicular to the plane of FIG. 34).

The first luminance enhancement film 64 is provided in the Z-directionwith respect to the detection line RL. The second luminance enhancementfilm 65 is provided on the surface of the first luminance enhancementfilm 64 facing in the Z-direction.

FIG. 35 is a schematic diagram of a third example of a sectionalstructure of the light emitter in the display apparatus according to thefifth embodiment. The light emitter BL illustrated in FIG. 35corresponds to that in the second example of the sectional structure ofthe display apparatus if illustrated in FIG. 31.

The detection line RL is provided on the surface of the light guideplate 61 facing in the Z-direction. The detection line RL extends in theY-direction (direction perpendicular to the plane of FIG. 35). Thereflective plate 62 is provided in the opposite direction of theZ-direction with respect to the detection line RL.

FIG. 36 is a schematic diagram of a fourth example of a sectionalstructure of the light emitter in the display apparatus according to thefifth embodiment. The light emitter BL illustrated in FIG. 36corresponds to that in the third example of the sectional structure ofthe display apparatus if illustrated in FIG. 32.

A reflective plate 62 is provided on the surface of the light guideplate 61 facing in the Z-direction. The reflective plate 62 reflects, inthe Z-direction, light output from the light guide plate 61 andtraveling in the opposite direction of the Z-direction. With thismechanism, the reflective plate 62 can effectively direct the light Lo,which is output from the light source 66, toward the panel PNLf.

The detection line RL is provided on the surface of the light guideplate 61 facing in the Z-direction. The detection line RL extends in theY-direction (direction perpendicular to the plane of FIG. 36). Thediffusion film 63 is provided in the Z-direction with respect to thedetection line RL.

Illustration and explanation of the flowchart of the exemplary operationperformed by the display apparatus according to the fifth embodiment areomitted because it is the same as the flowchart (refer to FIGS. 10 and13) of the first and the second exemplary operations performed by thedisplay apparatus according to the first embodiment.

The display apparatus according to the fifth embodiment has thefollowing characteristics besides the characteristics of the displayapparatus according to the first embodiment. The display apparatusaccording to the fifth embodiment also has characteristics other thanthose described below. The display apparatus according to the fifthembodiment includes the detection lines RL arranged in the oppositedirection of the Z-direction with respect to the panel PNLf. In thedisplay apparatus according to the fifth embodiment, the image IMG(refer to FIG. 1) does not pass through the detection lines RL.Consequently, the display apparatus according to the fifth embodimentcan increase the transmittance of the image IMG and improve the displayquality. The display apparatus may supply a positive- ornegative-polarity signal to at least one signal line SL and detect adetection signal with at least one detection line RL corresponding tothe at least one signal line SL supplied with the positive- ornegative-polarity signal.

6. Sixth Embodiment

FIG. 37 is a block diagram of the configuration of a display apparatuswith a touch detection function according to a sixth embodiment.

A display apparatus with a touch detection function 1 g according to thepresent embodiment includes a panel PNLg, the light emitter BL, and acontroller CTLg. The panel PNLg includes the display device DSP, thedetector DET, and a touch detector TDET. The display device DSP displaysan image. The detector DET detects an image. The touch detector TDETdetects contact or proximity of an object to be detected OBJ with or toa touch detection surface IS.

The display apparatus with a touch detection function 1 g according tothe present embodiment has the image display period for displaying animage, the image detection period for detecting an image, and a touchdetection period for detecting a touch. In this disclosure, a touch maybe a state where an object to be detected is in contact with orproximity to a touch detection electrode or touch detection surface. Thedisplay apparatus with a touch detection function 1 g according to thepresent embodiment employs a column inversion driving method ofinverting the polarity of image signals alternately in columns (pixelcolumns) adjacent to each other, which will be described later. Theimage detection period includes a period for detecting apositive-polarity image and a period for detecting a negative-polarityimage.

The display device DSP, the detector DET, and the touch detector TDETmay be provided as an in-cell apparatus in which they are integrated.Alternatively, the display device DSP, the detector DET, and the touchdetector TDET may be provided as an on-cell apparatus in which thedetector DET and the touch detector TDET are mounted on the displaydevice DSP.

The controller CTLg includes the display controller 2, the detectioncontroller 3, and a touch detection controller 71. The displaycontroller 2 controls the display device DSP and the light emitter BL.The detection controller 3 reads detection signals from the detector DETand outputs detection image data to the host HST based on the detectionsignals. The touch detection controller 71 controls touch detection.

The detection controller 3 and the touch detection controller 71 are anIC chip mounted on printed circuits (e.g., flexible printed circuits)coupled to the glass substrate of the display device DSP, for example.

FIG. 38 is a diagram of the module configuration of the displayapparatus with a touch detection function according to the sixthembodiment.

The panel PNLg includes a substrate 4 g, a drive electrode driver 9 g,and a COF 12 g. The substrate 4 g includes a first substrate 5 g and asecond substrate 6 g. The second substrate 6 g is disposed in theZ-direction with respect to the first substrate 5 g and faces the firstsubstrate 5 g with a predetermined space interposed therebetween.

The configuration of the panel PNLg of the display apparatus with atouch detection function 1 g according to the present embodiment isdifferent from that of the panel PNLb (refer to FIG. 15) of the displayapparatus according to the second embodiment in that the detection linesRL are provided to the second substrate 6 g. The detection lines RL arearranged one for every two rows of the pixels Pix and extend in theX-direction. In other words, the number of detection lines RL is (M/2).The configuration described above is given by way of example only, andthe detection lines RL are not necessarily arranged one for every tworows of the pixels Pix. The detection lines RL may be arranged one forevery one or every three or more rows of the pixels Pix. The detectionlines RL are coupled to the COF 12 g.

The drive electrodes COML correspond to the detector DET illustrated inFIG. 37. The drive electrodes COML and the detection lines RL correspondto the touch detector TDET illustrated in FIG. 37. The COG 11, thevertical driver 7, the horizontal driver 8, and the drive electrodedriver 9 g correspond to the display controller 2 illustrated in FIG.37. The COF 12 g corresponds to the detection controller 3 and the touchdetection controller 71 illustrated in FIG. 37.

The following describes the basic principle of mutual capacitance touchdetection performed by the display apparatus with a touch detectionfunction 1 g according to the present embodiment with reference to FIGS.39 to 41.

FIG. 39 is a diagram for explaining the basic principle of mutualcapacitance touch detection and illustrates a state where an object tobe detected is in contact with or in proximity to a touch detectionelectrode. FIG. 40 is a diagram for explaining an example of anequivalent circuit in mutual capacitance touch detection. FIG. 41 is adiagram of an example of waveforms of a drive signal and a detectionsignal in mutual capacitance touch detection. FIG. 40 also illustrates adetection circuit.

As illustrated in FIG. 39, for example, a capacitance element C11includes a pair of electrodes, that is, a drive electrode E1 and a touchdetection electrode E2 facing each other with a dielectric D interposedtherebetween. As illustrated in FIG. 40, a first end of the capacitanceelement C11 is coupled to an alternating-current (AC) signal source(drive signal source) S, and a second end thereof is coupled to avoltage detector (touch detector) DE. The voltage detector DE is anintegration circuit included in the COF 12 g, for example.

When the AC signal source S applies an AC rectangular wave Sg having apredetermined frequency (e.g., several kilohertz to several hundredkilohertz) to the drive electrode E1 (first end of the capacitanceelement C11), an output waveform (touch detection signal Vdet1) appearsvia the voltage detector DE coupled to the touch detection electrode E2(second end of the capacitance element C11). The AC rectangular wave Sgcorresponds to the touch detection drive signal Vcomtm, which will bedescribed later.

In a state where an object to be detected is not in contact with nor inproximity to the touch detection electrode (non-contact state), anelectric current I₀ depending on the capacitance value of thecapacitance element C11 flows in association with charge and dischargeof the capacitance element C11. As illustrated in FIG. 41, the voltagedetector DE converts fluctuations in the electric current I₀ accordingto the AC rectangular wave Sg into fluctuations in the voltage (waveformV₀ indicated by the solid line).

By contrast, in a state where an object to be detected is in contactwith or in proximity to the touch detection electrode (contact state),capacitance C12 formed by a finger is in contact with or in proximity tothe touch detection electrode E2 as illustrated in FIG. 39. In thecontact state, fringe capacitance between the drive electrode E1 and thetouch detection electrode E2 is blocked by the finger. As a result, thecapacitance element C11 acts as a capacitance element C11 a having acapacitance value smaller than that of the capacitance element C11. Inthe equivalent circuit illustrated in FIG. 40, an electric current I₁flows through the capacitance element C11 a.

As illustrated in FIG. 41, the voltage detector DE converts fluctuationsin the electric current I₁ in accordance with the AC rectangular wave Sginto fluctuations in the voltage (waveform V₁ indicated by the dottedline). In this case, the waveform V₁ has amplitude smaller than that ofthe waveform V₀. Consequently, an absolute value |ΔV| of the voltagedifference between the waveform V₀ and the waveform V₁ varies dependingon an effect of the object to be detected. To accurately detect theabsolute value |ΔV| of the voltage difference between the waveform V₀and the waveform V₁, the voltage detector DE preferably operates with aperiod Res for resetting charge and discharge of a capacitor inaccordance with the frequency of the AC rectangular wave Sg by switchingin the circuit.

FIG. 42 is a perspective view of an exemplary configuration of the driveelectrodes and the detection lines in the display apparatus with a touchdetection function according to the sixth embodiment. The driveelectrodes COML according to the present exemplary configuration servenot only as drive electrodes of the display device DSP but also as driveelectrodes of the touch detector TDET.

The drive electrodes COML face the pixel electrodes PE (refer to FIG. 3)in a direction perpendicular to the surface of the first substrate 5 g.The touch detector TDET includes the drive electrodes COML provided tothe first substrate 5 g and the detection lines RL provided to thesecond substrate 6 g.

The detection lines RL have stripe electrode patterns extending in adirection intersecting the extending direction of the electrode patternsof the drive electrodes COML. The detection lines RL face the driveelectrodes COML in the direction perpendicular to the surface of thefirst substrate 5 g. The electrode patterns of the detection lines RLare coupled to the COF 12 g.

The electrode patterns of the drive electrodes COML and those of thedetection lines RL intersecting each other form capacitance at theintersections. In the touch detector TDET, the drive electrode driver 9g applies touch detection drive signals Vcomtm to the drive electrodesCOML. As a result, the detection lines RL output touch detection signalsVdet1, and thus touch detection is performed.

In other words, the drive electrode COML corresponds to the driveelectrode E1 in the basic principle of mutual capacitance touchdetection illustrated in FIGS. 39 to 41, and the detection line RLcorresponds to the touch detection electrode E2. The touch detector TDETdetects a touch based on the basic principle.

As described above, the touch detector TDET includes the detection linesRL that generate mutual capacitance with either the pixel electrodes PEor the drive electrodes COML (e.g., the drive electrodes COML). Based ona change in the mutual capacitance, the touch detector TDET performstouch detection.

The electrode patterns of the drive electrodes COML and those of thedetection lines RL intersecting each other serve as a mutual capacitivetouch sensor formed in a matrix (row-column configuration). The COF 12 gscans the entire input surface IS of the touch detector TDET, therebydetecting the position and the contact area where the object to bedetected OBJ is in contact with or in proximity to the input surface IS.

Specifically, in a touch detection operation, the drive electrode driver9 g drives a plurality of drive electrode blocks in the touch detectorTDET to sequentially linearly scan each of the drive electrode blocks ina time-division manner, each drive electrode block including a pluralityof drive electrodes COML. As a result, each drive electrode block (onedetection block) is sequentially selected in a scanning direction Scan.The touch detector TDET outputs the touch detection signals Vdet1 fromthe detection lines RL. The touch detector TDET thus performs touchdetection on one detection block.

The detection lines RL or the drive electrodes COML (drive electrodeblocks) do not necessarily have a shape divided into a plurality ofstripe patterns. The detection lines RL or the drive electrodes COML(drive electrode blocks) may have a comb shape, for example. Thedetection lines RL or the drive electrodes COML (drive electrode blocks)simply need to have a shape divided into a plurality of parts. The shapeof slits separating the drive electrodes COML from one another may be astraight line or a curved line.

In an example of an operating method employed by the display apparatuswith a touch detection function 1 g, the display apparatus with a touchdetection function 1 g performs a touch detection operation (the touchdetection period) and a display operation (the image display period andthe image detection period) in a time-division manner. The touchdetection operation and the display operation may be performed in anydivision manner.

FIG. 43 is a diagram of the configuration of the horizontal driver, thedrive electrode driver, and the COF of the display apparatus with atouch detection function according to the sixth embodiment. FIG. 43illustrates a portion of the horizontal driver 8 that drives the pixelsPix of four columns, a portion of the drive electrode driver 9 g thatdrives the pixels Pix of four columns, a portion of the COF 12 g thatreads touch detection signals of two rows, and a portion of the COF 12 gthat reads detection signals of the pixels Pix of four columns.

The configuration of the panel PNLg of the display apparatus with atouch detection function 1 g according to the present embodiment isdifferent from that of the panel PNLb of the display apparatus accordingto the second embodiment in that the drive electrode driver 9 g furtherincludes a touch detection drive signal output amplifier TDAMP and ascanning circuit SC. The COF 12 g includes a touch detection circuit 12g 2 besides an image detection circuit 12 g 1. The circuit configurationof the image detection circuit 12 g 1 is the same as the circuitconfiguration (illustrated in FIG. 17) of the COF 12 of the displayapparatus according to the second embodiment.

When a control signal EXVCOM is supplied from the COG 11 (refer to FIG.38), the scanning circuit SC sequentially couples the touch detectiondrive signal output amplifier TDAMP to the drive electrodes COML. At afirst touch detection timing, for example, the scanning circuit SCcouples the touch detection drive signal output amplifier TDAMP to thefirst drive electrode block. At a second touch detection timing, thescanning circuit SC couples the touch detection drive signal outputamplifier TDAMP to the second drive electrode block.

The touch detection circuit 12 g 2 includes detection circuits D₁ and D₂serving as integration circuits. The integration circuits are each thedetection circuit INT₁ or INT₂ illustrated in FIG. 17, for example. Aswitch SW₆₁ is disposed between the detection circuit D₁ and thedetection line RL₁. When a control signal SEL₅ supplied from the COG 11(refer to FIG. 38) is at a high level, the switch SW₆₁ electricallycouples the detection circuit D₁ to the drive electrode COML₁. When thecontrol signal SEL₅ is at a low level, the switch SW₆₁ cuts offelectrical coupling between the detection circuit D₁ and the driveelectrode COML₁.

In the image display period and the image detection period, the controlsignal SEL₅ is at a low level. As a result, the switch SW₆₁ cuts offelectrical coupling between the detection circuit D₁ and the driveelectrode COML₁. In the touch detection period, the control signal SEL₅is at a high level. As a result, the switch SW₆₁ electrically couplesthe detection circuit D₁ to the drive electrode COML₁, thereby supplyingthe touch detection drive signal Vcomtm to the detection circuit D₁. Thedetection circuit D₁ compares the touch detection signal with areference potential to read the touch detection signal.

A switch SW₆₂ is disposed between the detection circuit D₂ and thedetection line RL₂. When the control signal SEL₅ supplied from the COG11 (refer to FIG. 38) is at a high level, the switch SW₆₂ electricallycouples the detection circuit D₂ to the drive electrode COML₂. When thecontrol signal SEL₅ is at a low level, the switch SW₆₂ cuts offelectrical coupling between the detection circuit D₂ and the driveelectrode COML₂.

In the image display period and the image detection period, the controlsignal SEL₅ is at a low level. As a result, the switch SW₆₂ cuts offelectrical coupling between the detection circuit Da and the driveelectrode COML₂. In the touch detection period, the control signal SEL₅is at a high level. As a result, the switch SW₆₂ electrically couplesthe detection circuit Da to the drive electrode COML₂, thereby supplyingthe touch detection drive signal Vcomtm to the detection circuit Da. Thedetection circuit Da compares the touch detection signal with areference potential to read the touch detection signal.

6-1. Exemplary Operation Performed by the Display Apparatus According tothe Sixth Embodiment

FIG. 44 is a diagram of an operating sequence in an exemplary operationperformed by the display apparatus with a touch detection functionaccording to the sixth embodiment. FIG. 44 illustrates an operatingsequence performed by the display apparatus with a touch detectionfunction 1 g on two frames. As illustrated in FIG. 44, the displayapparatus with a touch detection function 1 g sequentially performscontrol on the L units (refer to FIG. 6) from the first unit U₁ to theL-th unit U_(L) in the first frame (from timing t₁₀₀ to timing t₁₀₇) andthe second frame (from timing t₁₀₇ to timing t₁₁₄).

From timing t₁₀₀ to timing t₁₀₁, the display apparatus with a touchdetection function 1 g performs image detection (detection of thepositive-polarity pixel signals) and image display for the first frameon the (M/L) horizontal lines included in the first unit U₁. In theimage detection performed from timing t₁₀₀ to timing t₁₀₁, the displayapparatus with a touch detection function 1 g applies only thepositive-polarity pixel signals to perform image detection (detection ofthe positive-polarity pixel signals). In the image display performedfrom timing t₁₀₀ to timing t₁₀₁, the display apparatus with a touchdetection function 1 g applies both the positive- and thenegative-polarity pixel signals to display an image.

From timing t₁₀₁ to timing t₁₀₂, the display apparatus with a touchdetection function 1 g performs touch detection on the (M/L) horizontallines included in the first unit U₁.

From timing t₁₀₂ to timing t₁₀₃, the display apparatus with a touchdetection function 1 g performs image detection (detection of thepositive-polarity pixel signals) and image display for the first frameon the (M/L) horizontal lines included in the second unit U₂. In theimage detection performed from timing t₁₀₂ to timing t₁₀₃, the displayapparatus with a touch detection function 1 g applies only thepositive-polarity pixel signals to perform image detection (detection ofthe positive-polarity pixel signals). In the image display performedfrom timing t₁₀₂ to timing t₁₀₃, the display apparatus with a touchdetection function 1 g applies both the positive- and thenegative-polarity pixel signals to display an image.

From timing t₁₀₃ to timing t₁₀₄, the display apparatus with a touchdetection function 1 g performs touch detection on the (M/L) horizontallines included in the second unit U₂.

From timing t₁₀₄ to timing t₁₀₅, similarly to from timing t₁₀₂ to timingt₁₀₄, the display apparatus with a touch detection function 1 g performsimage display and image detection (detection of the positive-polaritypixel signals). From timing tins to timing t₁₀₆, the display apparatuswith a touch detection function 1 g performs image detection (detectionof the positive-polarity pixel signals) and image display for the firstframe on the (M/L) horizontal lines included in the L-th unit U_(L). Inthe image detection performed from timing t₁₀₅ to timing t₁₀₆, thedisplay apparatus with a touch detection function 1 g applies only thepositive-polarity pixel signals to perform image detection (detection ofthe positive-polarity pixel signals). In the image display performedfrom timing tins to timing t₁₀₆, the display apparatus with a touchdetection function 1 g applies both the positive- and thenegative-polarity pixel signals to display an image. From timing t₁₀₆ totiming t₁₀₇, the display apparatus with a touch detection function 1 gperforms touch detection on the (M/L) horizontal lines included in theL-th unit U_(L).

From timing t₁₀₇ to timing tog, the display apparatus with a touchdetection function 1 g performs image detection (detection of thenegative-polarity pixel signals) and image display for the second frameon the (M/L) horizontal lines included in the first unit U₁. In theimage detection performed from timing t₁₀₇ to timing tog, the displayapparatus with a touch detection function 1 g applies only thenegative-polarity pixel signals to perform image detection (detection ofthe negative-polarity pixel signals). In the image display performedfrom timing t₁₀₇ to timing tog, the display apparatus with a touchdetection function 1 g applies both the positive- and thenegative-polarity pixel signals to display an image.

From timing tog to timing t₁₀₉, the display apparatus with a touchdetection function 1 g performs touch detection on the (M/L) horizontallines included in the first unit U₁.

From timing t₁₀₉ to timing t₁₁₀, the display apparatus with a touchdetection function 1 g performs image detection (detection of thenegative-polarity pixel signals) and image display for the second frameon the (M/L) horizontal lines included in the second unit U₂. In theimage detection performed from timing t₁₀₉ to timing t₁₁₀, the displayapparatus with a touch detection function 1 g applies only thenegative-polarity pixel signals to perform image detection (detection ofthe negative-polarity pixel signals). In the image display performedfrom timing t₁₀₉ to timing t₁₁₀, the display apparatus with a touchdetection function 1 g applies both the positive- and thenegative-polarity pixel signals to display an image.

From timing t₁₁₀ to timing t₁₁₁, the display apparatus with a touchdetection function 1 g performs touch detection on the (M/L) horizontallines included in the second unit U₂.

From timing t₁₁₁ to timing t₁₁₂, similarly to from timing t₁₀₉ to timingt₁₁₁, the display apparatus with a touch detection function 1 g performsimage display and image detection (detection of the negative-polaritypixel signals). From timing t₁₁₂ to timing t₁₁₃, the display apparatuswith a touch detection function 1 g performs image detection (detectionof the negative-polarity pixel signals) and image display for the secondframe on the (M/L) horizontal lines included in the L-th unit U_(L). Inthe image detection performed from timing t₁₁₂ to timing t₁₁₃, thedisplay apparatus with a touch detection function 1 g applies only thenegative-polarity pixel signals to perform image detection (detection ofthe negative-polarity pixel signals). In the image display performedfrom timing t₁₁₂ to timing t₁₁₃, the display apparatus with a touchdetection function 1 g applies both the positive- and thenegative-polarity pixel signals to display an image.

From timing t₁₁₃ to timing t₁₁₄, the display apparatus with a touchdetection function 1 g performs touch detection on the (M/L) horizontallines included in the L-th unit U_(L).

FIG. 45 is a diagram of an operating timing in an exemplary operationperformed by the display apparatus with a touch detection functionaccording to the sixth embodiment.

The period from timing t₁₂₀ of the first rising edge of the timingsignal TSVD to timing t₁₃₂ of the second rising edge of the timingsignal TSVD corresponds to the period of image detection, image display,and touch detection of the first frame. The period after timing t₁₃₂ ofthe second rising edge of the timing signal TSVD corresponds to theperiod of image detection, image display, and touch detection of thesecond frame.

The timing signal HSYNC for detection control output from the COG 11 tothe COF 12 g has the same frequency as that of the horizontalsynchronization signal for display control for displaying an image onthe display device DSP by the COG 11, for example.

During the entire period, the COG 11 outputs the control signals SEL₁and SEL₂ (refer to FIG. 43) at a high level to the horizontal driver 8.As a result, the switches SW₁ to SW₁₂ are turned on.

The period from timing t₁₂₁ to timing t₁₂₄ corresponds to apositive-polarity image detection and display writing (image display)period for the first horizontal line of the first frame.

At timing t₁₂₁, the host HST outputs image data for the first horizontalline of the first frame to the COG 11. The COG 11 temporarily stores theimage data for the first horizontal line of the first frame suppliedfrom the host HST in the buffer 11 a (refer to FIG. 38). The buffer 11 asimply needs to have storage capacity large enough to store thereinimage data of one horizontal line.

The period from timing t₁₂₁ to timing t₁₂₂, which is a predeterminedtime after timing t₁₂₁, corresponds to a precharge period for the signallines SL.

From timing t₁₂₁ to timing t₁₂₂, the horizontal driver 8 outputs theground potential GND to all the signal lines SL, thereby precharging allthe signal lines SL with the ground potential GND.

The period from timing t₁₂₂ to timing t₁₂₃ corresponds to thepositive-polarity image detection period for the first horizontal lineof the first frame.

At timing t₁₂₂, the COG 11 causes the horizontal driver 8 to output thepositive-polarity pixel signals for the first horizontal line of thefirst frame based on the image data for the first horizontal line of thefirst frame stored in the buffer 11 a. The horizontal driver 8 outputsthe positive-polarity pixel signals SIG_(PLUS) for the first horizontalline of the first frame to one group of the two groups (the group of theodd-numbered signal lines SL and the group of the even-numbered signallines SL) of the N signal lines SL. The horizontal driver 8 maintainsthe electric potential (ground potential GND) of the other group of thetwo groups of the N signal lines SL.

The horizontal driver 8, for example, outputs the positive-polaritypixel signals SIG_(PLUS) for the first horizontal line of the firstframe to the group of the odd-numbered signal lines SL (refer to thesignal lines SL₁, SL₃, SL₅, . . . in FIG. 43) out of the N signal linesSL. The horizontal driver 8 maintains the electric potential (groundpotential GND) of the group of the even-numbered signal lines SL (referto the signal lines SL₂, SL₄, SL₆, . . . in FIG. 43) out of the N signallines SL.

From timing t₁₂₁ to timing t₁₂₃, the COG 11 outputs the control signalSEL₃ (refer to FIG. 43) at a low level to the drive electrode driver 9g. As a result, the switches SW₂₁ and SW₂₂ are turned off. Consequently,all the drive electrodes COML are brought into a floating state.

Referring back to FIG. 43, when the drive electrode COML₁ is in afloating state, the signal lines SL₁, SL₃, and SL₅ are capacitivelycoupled to the drive electrode COML₁. As a result, the detection signalis generated in the drive electrode COML₁ due to the pixel signalsSIG_(PLUS) supplied to the signal lines SL₁, SL₃, and SL₅. The COG 11changes the control signal SEL₄ to a high level at a timing based on thetiming signal HSYNC, for example, at timing t₁₂₂. As a result, theswitch SW₃₁ is turned on at timing t₁₂₂. The detection circuit INT₁ isthe detection circuit INT₁ or INT₂ illustrated in FIG. 17, for example.The detection circuit INT₁ reads the detection signal at timing t₁₂₂.The COF 12 g performs sampling and A/D conversion on the detectionsignal, thereby obtaining the positive-polarity detection pixel data.The detection signal is a spike signal similarly to that illustrated inFIG. 25 and other figures. The COF 12 g may read the peak voltage of thedetection signal, thereby obtaining the positive-polarity detectionpixel data.

The period from timing t₁₂₃ to timing t₁₂₄ corresponds to the displaywriting (image display) period for the first horizontal line of thefirst frame.

At timing t₁₂₃, the COG 11 causes the horizontal driver 8 to output thepixel signals based on the image data for the first horizontal line ofthe first frame stored in the buffer 11 a. The horizontal driver 8maintains the electric potential (positive-polarity pixel signalsSIG_(PLUS) for the first horizontal line of the first frame) of onegroup of the two groups (the group of the odd-numbered signal lines SLand the group of the even-numbered signal lines SL) of the N signallines SL. The horizontal driver 8 outputs the negative-polarity pixelsignals SIG_(MINUS) for the first horizontal line of the first frame tothe other group of the two groups of the N signal lines SL.

The horizontal driver 8, for example, maintains the electric potential(positive-polarity pixel signals SIG_(PLUS) for the first horizontalline of the first frame) of the group of the odd-numbered signal linesSL (refer to the signal lines SL₁, SL₃, SL₅, . . . in FIG. 43) out ofthe N signal lines SL. The horizontal driver 8 outputs thenegative-polarity pixel signals SIG_(MINUS) for the first horizontalline of the first frame to the group of the even-numbered signal linesSL (refer to the signal lines SL₂, SL₄, SL₆, . . . in FIG. 43) out ofthe N signal lines SL.

From timing t₁₂₃ to timing t₁₂₄, the COG 11 outputs the control signalSEL₃ (refer to FIG. 43) at a high level to the drive electrode driver 9g. As a result, the switches SW₂₁ and SW₂₂ are turned on. The driveelectrode driver 9 g outputs the drive signals VCOM to all the driveelectrodes COML. Consequently, an electric field is formed between thepixel electrodes PE (refer to FIG. 3) and the drive electrodes COML,thereby displaying an image.

From timing t₁₂₃ to timing t₁₂₄, the COG 11 changes the control signalSEL₄ (refer to FIG. 43) to a low level. As a result, the switches SW₃₁and SW₃₂ are turned off, whereby neither the detection circuit INT₁ northe detection circuit INT₂ reads the drive signals VCOM.

The period from timing t₁₂₄ to timing t₁₂₇ corresponds to apositive-polarity image detection and display writing (image display)period for the second horizontal line of the first frame.

At timing t₁₂₄, the host HST outputs image data for the secondhorizontal line of the first frame to the COG 11. The COG 11 temporarilystores the image data for the second horizontal line of the first framesupplied from the host HST in the buffer 11 a (refer to FIG. 38).

The period from timing t₁₂₄ to timing t₁₂₅, which is a predeterminedtime after timing t₁₂₄, corresponds to a precharge period for the signallines SL.

From timing t₁₂₄ to timing t₁₂₅, the horizontal driver 8 outputs theground potential GND to one group of the two groups (the group of theodd-numbered signal lines SL and the group of the even-numbered signallines SL) of the N signal lines SL. The horizontal driver 8 thusprecharges the group of the odd-numbered or the even-numbered signallines SL in the N signal lines SL with the ground potential GND. Fromtiming t₁₂₄ to timing t₁₂₅, the horizontal driver 8 maintains theelectric potential (negative-polarity pixel signals SIG_(MINUS) for thefirst horizontal line of the first frame) of the other group of the twogroups of the N signal lines SL.

The horizontal driver 8, for example, outputs the ground potential GNDto the group of the odd-numbered signal lines SL (refer to the signallines SL₁, SL₃, SL₅, . . . in FIG. 43) out of the N signal lines SL. Thehorizontal driver 8 maintains the electric potential (negative-polaritypixel signals SIG_(MINUS) for the first horizontal line of the firstframe) of the group of the even-numbered signal lines SL (refer to thesignal lines SL₂, SL₄, SL₆, . . . in FIG. 43) out of the N signal linesSL.

The period from timing t₁₂₅ to timing t₁₂₆ corresponds to thepositive-polarity image detection period for the second horizontal lineof the first frame.

At timing t₁₂₅, the COG 11 causes the horizontal driver 8 to output thepositive-polarity pixel signals based on the image data for the secondhorizontal line of the first frame stored in the buffer 11 a. Thehorizontal driver 8 outputs the positive-polarity pixel signalsSIG_(PLUS) for the second horizontal line of the first frame to onegroup of the two groups (the group of the odd-numbered signal lines SLand the group of the even-numbered signal lines SL) of the N signallines SL. The horizontal driver 8 maintains the electric potential(negative-polarity pixel signals SIG_(MINUS) for the first horizontalline of the first frame) of the other group of the two groups of the Nsignal lines SL.

The horizontal driver 8, for example, outputs the positive-polaritypixel signals SIG_(PLUS) for the second horizontal line of the firstframe to the group of the odd-numbered signal lines SL (refer to thesignal lines SL₁, SL₃, SL₅, . . . in FIG. 43) out of the N signal linesSL. The horizontal driver 8 maintains the electric potential(negative-polarity pixel signals SIG_(MINUS) for the first horizontalline of the first frame) of the group of the even-numbered signal linesSL (refer to the signal lines SL₂, SL₄, SL₆, . . . in FIG. 43) out ofthe N signal lines SL.

From timing t₁₂₅ to timing t₁₂₆, the COG 11 outputs the control signalSEL₃ (refer to FIG. 43) at a low level to the drive electrode driver 9g. As a result, the switches SW₂₁ and SW₂₂ are turned off. Consequently,all the drive electrodes COML are brought into a floating state.

Referring back to FIG. 43, when the drive electrode COML₁ is in afloating state, the signal lines SL₁, SL₃, and SL₅ are capacitivelycoupled to the drive electrode COML₁. As a result, the detection signalis generated in the drive electrode COML₁ due to the pixel signalsSIG_(PLUS) supplied to the signal lines SL₁, SL₃, and SL₅. The COG 11changes the control signal SEL₄ to a high level at a timing based on thetiming signal HSYNC, for example, at timing t₁₂₅. As a result, theswitch SW₃₁ is turned on at timing t₁₂₅. The detection circuit INT₁reads the detection signal at timing t₁₂₅. The COF 12 g performssampling and A/D conversion on the detection signal, thereby obtainingthe positive-polarity detection pixel data. The COF 12 g may read thepeak voltage of the detection signal, thereby obtaining thepositive-polarity detection pixel data.

The period from timing t₁₂₆ to timing t₁₂₇ corresponds to the displaywriting (image display) period for the second horizontal line of thefirst frame.

At timing t₁₂₆, the COG 11 causes the horizontal driver 8 to output thepixel signals based on the image data for the second horizontal line ofthe first frame stored in the buffer 11 a. The horizontal driver 8maintains the electric potential (positive-polarity pixel signalsSIG_(PLUS) for the second horizontal line of the first frame) of onegroup of the two groups (the group of the odd-numbered signal lines SLand the group of the even-numbered signal lines SL) of the N signallines SL. The horizontal driver 8 outputs the negative-polarity pixelsignals SIG_(MINUS) for the second horizontal line of the first frame tothe other group of the two groups of the N signal lines SL.

The horizontal driver 8, for example, maintains the electric potential(positive-polarity pixel signals SIG_(PLUS) for the second horizontalline of the first frame) of the group of the odd-numbered signal linesSL (refer to the signal lines SL₁, SL₃, SL₅, . . . in FIG. 43) out ofthe N signal lines SL. The horizontal driver 8 outputs thenegative-polarity pixel signals SIG_(MINUS) for the second horizontalline of the first frame to the group of the even-numbered signal linesSL (refer to the signal lines SL₂, SL₄, SL₆, . . . in FIG. 43) out ofthe N signal lines SL.

From timing t₁₂₆ to timing t₁₂₇, the COG 11 outputs the control signalSEL₃ (refer to FIG. 43) at a high level to the drive electrode driver 9g. As a result, the switches SW₂₁ and SW₂₂ are turned on. The driveelectrode driver 9 g outputs the drive signals VCOM to all the driveelectrodes COML. Consequently, an electric field is formed between thepixel electrodes PE (refer to FIG. 3) and the drive electrodes COML,thereby displaying an image.

From timing t₁₂₆ to timing t₁₂₇, the COG 11 changes the control signalSEL₄ (refer to FIG. 43) to a low level. As a result, the switch SW₃₁ isturned off, whereby the detection circuit INT₁ does not read the drivesignals VCOM.

Similarly, the COG 11 and the COF 12 g perform positive-polarity imagedetection and display writing (image display) of the third to M-thhorizontal lines of the first frame.

The period from timing teas to timing t₁₃₁ corresponds to the touchdetection period for the first unit U₁ of the first frame. The touchdetection period will be described later in detail.

The period from timing t₁₃₃ to timing t₁₃₆ corresponds to anegative-polarity image detection and display writing (image display)period for the first horizontal line of the second frame.

At timing t₁₃₃, the host HST outputs image data for the first horizontalline of the second frame to the COG 11. The COG 11 temporarily storesthe image data for the first horizontal line of the second framesupplied from the host HST in the buffer 11 a (refer to FIG. 38). Thebuffer 11 a simply needs to have storage capacity large enough to storetherein image data of one horizontal line.

The period from timing t₁₃₃ to timing t₁₃₄, which is a predeterminedtime after timing t₁₃₃, corresponds to a precharge period for the signallines SL.

From timing t₁₃₃ to timing t₁₃₄, the horizontal driver 8 outputs theground potential GND to all the signal lines SL, thereby precharging allthe signal lines SL with the ground potential GND.

The period from timing t₁₃₄ to timing t₁₃₅ corresponds to thenegative-polarity image detection period for the first horizontal lineof the second frame.

At timing t₁₃₄, the COG 11 causes the horizontal driver 8 to output thenegative-polarity pixel signals for the first horizontal line of thesecond frame based on the image data for the first horizontal line ofthe second frame stored in the buffer 11 a. The horizontal driver 8outputs the negative-polarity pixel signals SIG_(MINUS) for the firsthorizontal line of the second frame to one group of the two groups (thegroup of the odd-numbered signal lines SL and the group of theeven-numbered signal lines SL) of the N signal lines SL. The horizontaldriver 8 maintains the electric potential (ground potential GND) of theother group of the two groups of the N signal lines SL.

The horizontal driver 8, for example, outputs the negative-polaritypixel signals SIG_(MINUS) for the first horizontal line of the secondframe to the group of the even-numbered signal lines SL (refer to thesignal lines SL₂, SL₄, SL₆, . . . in FIG. 43) out of the N signal linesSL. The horizontal driver 8 maintains the electric potential (groundpotential GND) of the group of the odd-numbered signal lines SL (referto the signal lines SL₁, SL₃, SL₅, . . . in FIG. 43) out of the N signallines SL.

From timing t₁₃₄ to timing t₁₃₅, the COG 11 outputs the control signalSEL₃ (refer to FIG. 43) at a low level to the drive electrode driver 9g. As a result, the switches SW₂₁ and SW₂₂ are turned off. Consequently,all the drive electrodes COML are brought into a floating state.

Referring back to FIG. 43, when the drive electrode COML₁ is in afloating state, the signal lines SL₂, SL₄, and SL₆ are capacitivelycoupled to the drive electrode COML₁. As a result, the detection signalis generated in the drive electrode COML₁ due to the pixel signalsSIG_(MINUS) supplied to the signal lines SL₂, SL₄, and SL₆. The COG 11changes the control signal SEL₄ to a high level at a timing based on thetiming signal HSYNC, for example, at timing t₁₃₄. As a result, theswitch SW₃₁ is turned on at timing t₁₃₄. The detection circuit INT₁reads the detection signal at timing t₁₃₄. The COF 12 g performssampling and A/D conversion on the detection signal, thereby obtainingthe negative-polarity detection pixel data. The COF 12 g may read thepeak voltage of the detection signal, thereby obtaining thenegative-polarity detection pixel data.

The period from timing t₁₃₅ to timing t₁₃₆ corresponds to the displaywriting (image display) period for the first horizontal line of thesecond frame.

At timing t₁₃₅, the COG 11 causes the horizontal driver 8 to output thepixel signals based on the image data for the first horizontal line ofthe second frame stored in the buffer 11 a. The horizontal driver 8maintains the electric potential (negative-polarity pixel signalsSIG_(MINUS) for the first horizontal line of the second frame) of onegroup of the two groups (the group of the odd-numbered signal lines SLand the group of the even-numbered signal lines SL) of the N signallines SL. The horizontal driver 8 outputs the positive-polarity pixelsignals SIG_(PLUS) for the first horizontal line of the second frame tothe other group of the two groups of the N signal lines SL.

The horizontal driver 8, for example, maintains the electric potential(negative-polarity pixel signals SIG_(MINUS) for the first horizontalline of the second frame) of the group of the even-numbered signal linesSL (refer to the signal lines SL₂, SL₄, SL₆, . . . in FIG. 43) out ofthe N signal lines SL. The horizontal driver 8 outputs thepositive-polarity pixel signals SIG_(PLUS) for the first horizontal lineof the second frame to the group of the odd-numbered signal lines SL(refer to the signal lines SL₁, SL₃, SL₅, . . . in FIG. 43) out of the Nsignal lines SL.

From timing t₁₃₅ to timing t₁₃₆, the COG 11 outputs the control signalSEL₃ (refer to FIG. 43) at a high level to the drive electrode driver 9g. As a result, the switches SW₂₁ and SW₂₂ are turned on. The driveelectrode driver 9 g outputs the drive signals VCOM to all the driveelectrodes COML. Consequently, an electric field is formed between thepixel electrodes PE (refer to FIG. 3) and the drive electrodes COML,thereby displaying an image.

From timing t₁₃₅ to timing t₁₃₆, the COG 11 changes the control signalSEL₄ (refer to FIG. 43) to a low level. As a result, the switches SW₃₁and SW₃₂ are turned off, whereby neither the detection circuit INT₁ northe detection circuit INT₂ reads the drive signals VCOM.

The period after timing t₁₃₆ corresponds to a negative-polarity imagedetection and display writing (image display) period for the secondhorizontal line of the second frame.

At timing t₁₃₆, the host HST outputs image data for the secondhorizontal line of the second frame to the COG 11. The COG 11temporarily stores the image data for the second horizontal line of thesecond frame supplied from the host HST in the buffer 11 a (refer toFIG. 38).

The period from timing t₁₃₆ to timing t₁₃₇, which is a predeterminedtime after timing t₁₃₆, corresponds to a precharge period for the signallines SL.

From timing t₁₃₆ to timing t₁₃₇, the horizontal driver 8 outputs theground potential GND to one group of the two groups (the group of theodd-numbered signal lines SL and the group of the even-numbered signallines SL) of the N signal lines SL. The horizontal driver 8 thusprecharges the group of the odd-numbered or the even-numbered signallines SL in the N signal lines SL with the ground potential GND. Fromtiming t₁₃₆ to timing t₁₃₇, the horizontal driver 8 maintains theelectric potential (positive-polarity pixel signals SIG_(PLUS) for thefirst horizontal line of the second frame) of the other group of the twogroups of the N signal lines SL.

The horizontal driver 8, for example, outputs the ground potential GNDto the group of the even-numbered signal lines SL (refer to the signallines SL₂, SL₄, SL₆, . . . in FIG. 43) out of the N signal lines SL. Thehorizontal driver 8 maintains the electric potential (positive-polaritypixel signals SIG_(PLUS) for the first horizontal line of the secondframe) of the group of the odd-numbered signal lines SL (refer to thesignal lines SL₁, SL₃, SL₅, . . . in FIG. 43) out of the N signal linesSL.

The period from timing t₁₃₇ to timing t₁₃₈ corresponds to thenegative-polarity image detection period for the second horizontal lineof the second frame.

At timing t₁₃₇, the COG 11 causes the horizontal driver 8 to output thenegative-polarity pixel signals based on the image data for the secondhorizontal line of the second frame stored in the buffer 11 a. Thehorizontal driver 8 outputs the negative-polarity pixel signalsSIG_(MINUS) for the second horizontal line of the second frame to onegroup of the two groups (the group of the odd-numbered signal lines SLand the group of the even-numbered signal lines SL) of the N signallines SL. The horizontal driver 8 maintains the electric potential(positive-polarity pixel signals SIG_(PLUS) for the first horizontalline of the second frame) of the other group of the two groups of the Nsignal lines SL.

The horizontal driver 8, for example, outputs the negative-polaritypixel signals SIG_(MINUS) for the second horizontal line of the secondframe to the group of the even-numbered signal lines SL (refer to thesignal lines SL₂, SL₄, SL₆, . . . in FIG. 43) out of the N signal linesSL. The horizontal driver 8 maintains the electric potential(positive-polarity pixel signals SIG_(PLUS) for the first horizontalline of the second frame) of the group of the odd-numbered signal linesSL (refer to the signal lines SL₁, SL₃, SL₅, . . . in FIG. 43) out ofthe N signal lines SL.

From timing t₁₃₇ to timing t₁₃₈, the COG 11 outputs the control signalSEL₃ (refer to FIG. 43) at a low level to the drive electrode driver 9g. As a result, the switches SW₂₁ and SW₂₂ are turned off. Consequently,all the drive electrodes COML are brought into a floating state.

Referring back to FIG. 43, when the drive electrode COML₁ is in afloating state, the signal lines SL₂, SL₄, and SL₆ are capacitivelycoupled to the drive electrode COML₁. As a result, the detection signalis generated in the drive electrode COML₁ due to the pixel signalsSIG_(MINUS) supplied to the signal lines SL₂, SL₄, and SL₆. The COG 11changes the control signal SEL₄ to a high level at a timing based on thetiming signal HSYNC, for example, at timing t₁₃₇. As a result, theswitch SW₃₁ is turned on at timing t₁₃₇. The detection circuit INT₁reads the detection signal at timing t₁₃₇. The COF 12 g performssampling and A/D conversion on the detection signal, thereby obtainingthe negative-polarity detection pixel data. The COF 12 g may read thepeak voltage of the detection signal, thereby obtaining thenegative-polarity detection pixel data.

The period after timing t₁₃₈ corresponds to a display writing (imagedisplay) period for the second horizontal line of the second frame.

At timing t₁₃₈, the COG 11 causes the horizontal driver 8 to output thepixel signals based on the image data for the second horizontal line ofthe second frame stored in the buffer 11 a. The horizontal driver 8maintains the electric potential (negative-polarity pixel signalsSIG_(MINUS) for the second horizontal line of the second frame) of onegroup of the two groups (the group of the odd-numbered signal lines SLand the group of the even-numbered signal lines SL) of the N signallines SL. The horizontal driver 8 outputs the positive-polarity pixelsignals SIG_(PLUS) for the second horizontal line of the second frame tothe other group of the two groups of the N signal lines SL.

The horizontal driver 8, for example, maintains the electric potential(negative-polarity pixel signals SIG_(MINUS) for the second horizontalline of the second frame) of the group of the even-numbered signal linesSL (refer to the signal lines SL₂, SL₄, SL₆, . . . in FIG. 43) out ofthe N signal lines SL. The horizontal driver 8 outputs thepositive-polarity pixel signals SIG_(PLUS) for the second horizontalline of the second frame to the group of the odd-numbered signal linesSL (refer to the signal lines SL₁, SL₃, SL₅, . . . in FIG. 43) out ofthe N signal lines SL.

From timing t₁₃₈, the COG 11 outputs the control signal SEL₃ (refer toFIG. 43) at a high level to the drive electrode driver 9 g. As a result,the switches SW₂₁ and SW₂₂ are turned on. The drive electrode driver 9 goutputs the drive signals VCOM to all the drive electrodes COML.Consequently, an electric field is formed between the pixel electrodesPE (refer to FIG. 3) and the drive electrodes COML, thereby displayingan image.

Similarly, the COG 11 and the COF 12 g perform negative-polarity imagedetection and display writing (image display) of the third to M-thhorizontal lines of the second frame.

FIG. 46 is another diagram of the operating timing in the exemplaryoperation performed by the display apparatus with a touch detectionfunction according to the sixth embodiment. FIG. 46 illustrates theperiod from timing t₁₂₈ to timing t₁₃₁ in FIG. 45, that is, the touchdetection period for the first unit U₁ of the first frame in greaterdetail.

The timing signal TSHD for touch detection control output from the COG11 to the COF 12 g indicates the image display period, the imagedetection period, and the touch detection period. In the image displayperiod and the image detection period, the COG 11 outputs the timingsignal TSHD at a low level to the COF 12 g. In the touch detectionperiod, the COG 11 outputs the timing signal TSHD at a high level to theCOF 12 g.

The period from timing t₁₂₉ of the first rising edge of the controlsignal EXVCOM output from the COG 11 to the drive electrode driver 9 gto timing too of the second rising edge of the control signal EXVCOMcorresponds to the touch detection period for the first drive electrodeblock (one detection block). The period after timing t₁₃₀ of the secondrising edge of the control signal EXVCOM corresponds to the touchdetection period for the second and subsequent drive electrode blocks.

When receiving the control signal EXVCOM at timing t₁₂₉, the scanningcircuit SC (refer to FIG. 43) couples the touch detection drive signaloutput amplifier TDAMP to the first drive electrode block. The touchdetection drive signal output amplifier TDAMP outputs the touchdetection drive signal Vcomtm to the first drive electrode block.

From timing teas to timing t₁₃₁, the COG 11 outputs the control signalSEL₅ (refer to FIG. 43) at a high level to the COF 12 g. As a result,the switches SW₆₁ and SW₆₂ are turned on. The detection circuit D₁ readsthe touch detection signals at timing teas. The COF 12 g performssampling and A/D conversion on the touch detection signals, therebyobtaining touch detection data. The COF 12 g may read the peak voltageof the touch detection signals, thereby obtaining the touch detectiondata.

Similarly, the COG 11 and the COF 12 g perform touch detection on thesecond and subsequent drive electrode blocks.

FIG. 47 is a flowchart of an operation in an exemplary operationperformed by the display apparatus according to the sixth embodiment.The display apparatus with a touch detection function 1 g performs theoperation illustrated in FIG. 47 on a frame-by-frame basis.

Explanation of the processing from Step S300 to Step S308 is omittedbecause it is the same as the processing from Step S200 to Step S208 ofthe flowchart illustrated in FIG. 13 according to the first embodiment.

At Step S310, the host HST determines whether the variable i is equal toa multiple of (M/L), that is, whether image detection and image displayfor one unit is finished. If the host HST determines that the variable iis equal to a multiple of (M/L) (Yes at Step S310), the host HSTperforms the processing at Step S312. If the host HST determines thatthe variable i is not equal to a multiple of (M/L) (No at Step S310),the host HST performs the processing at Step S314.

At Step S312, the COG 11 and the COF 12 g detect a touch. The COG 11 andthe COF 12 g divide a plurality of drive electrode blocks into L groups.The COG 11 and the COF 12 g drive a group corresponding to the number ofthe unit subjected to image detection and image display, therebydetecting a touch.

Explanation of the processing from Step S314 to Step S328 is omittedbecause it is the same as the processing from Step S210 to Step S224 ofthe flowchart illustrated in FIG. 13 according to the first embodiment.

The panel PNLg of the display apparatus with a touch detection function1 g according to the sixth embodiment is applicable to a lateralelectric field mode liquid crystal display apparatus (refer to FIG. 4)and a vertical electric field mode liquid crystal display apparatus(refer to FIG. 14).

The display apparatus with a touch detection function 1 g according tothe sixth embodiment has the following characteristics besides thecharacteristics of the display apparatus according to the firstembodiment. The display apparatus with a touch detection functionaccording to the sixth embodiment also has characteristics other thanthose described below. The display apparatus with a touch detectionfunction 1 g according to the sixth embodiment can perform touchdetection besides image detection. The display apparatus may supply apositive-or negative-polarity signal to at least one signal line SL anddetect a detection signal with at least one drive electrode COMLcorresponding to the at least one signal line SL supplied with thepositive- or negative-polarity signal.

7. Seventh Embodiment

FIG. 48 is a diagram of the configuration of the horizontal driver, thedrive electrode driver, and the COF of a display apparatus with a touchdetection function according to a seventh embodiment. FIG. 48illustrates a portion of the horizontal driver 8 that drives the pixelsPix of four columns, a portion of a drive electrode driver 9 h thatdrives the pixels Pix of four columns, and a portion of the COF 12 thatreads detection signals of the pixels Pix of four columns in a panelPNLh.

The configuration of the panel PNLh of the display apparatus with atouch detection function according to the present embodiment isdifferent from that of the panel PNLc (refer to FIG. 21) of the displayapparatus according to the third embodiment in that the drive electrodedriver 9 h further includes the touch detection drive signal outputamplifier TDAMP and a switch SW₇₁.

When a control signal SEL₆ supplied from the COG 11 is at a high level,the switch SW₇₁ electrically couples the touch detection drive signaloutput amplifier TDAMP to the drive electrodes COML. When the controlsignal SEL₆ is at a low level, the switch SW₇₁ cuts off electricalcoupling between the touch detection drive signal output amplifier TDAMPand the drive electrodes COML. In the touch detection period, thecontrol signal SEL₆ is at a high level. As a result, the switch SW₇₁electrically couples the touch detection drive signal output amplifierTDAMP to the drive electrodes COML, thereby supplying touch detectiondrive signals Vcomts to the drive electrodes COML. In the image displayperiod and the image detection period, the control signal SEL₆ is at alow level. As a result, the switch SW₇₁ cuts off electrical couplingbetween the touch detection drive signal output amplifier TDAMP and thedrive electrodes COML, thereby supplying no touch detection drive signalVcomts to the drive electrodes COML. While the touch detection drivesignal output amplifier TDAMP in FIG. 48 supplies the touch detectiondrive signals Vcomts to all the drive electrodes COML, the configurationis not limited thereto. A plurality of switches may be provided betweenthe touch detection drive signal output amplifier TDAMP and therespective drive electrodes COML. With this configuration, the touchdetection drive signal output amplifier TDAMP may sequentially supplythe touch detection drive signal Vcomts to the drive electrodes COMLindividually. Alternatively, a plurality of touch detection drive signaloutput amplifiers TDAMP may be provided for the respective driveelectrodes COML. With this configuration, the touch detection drivesignal output amplifiers TDAMP may drive the respective drive electrodesCOML simultaneously to perform detection. Still alternatively, the driveelectrodes COML may be divided into a plurality of drive electrodeblocks, and a plurality of touch detection drive signal outputamplifiers TDAMP may be provided for the respective drive electrodeblocks. With this configuration, the touch detection drive signal outputamplifiers TDAMP may drive the drive electrodes COML in units of blocksto perform detection. Each of the touch detection drive signal outputamplifiers TDAMP may sequentially supply the touch detection drivesignal Vcomts to a plurality of drive electrodes COML in a correspondingone of the drive electrode blocks. Alternatively, the touch detectiondrive signal output amplifier TDAMP may supply the touch detection drivesignals Vcomts to all the drive electrodes COML in the corresponding onedrive electrode blocks.

The following describes the basic principle of self-capacitance touchdetection performed by the display apparatus with a touch detectionfunction according to the present embodiment with reference to FIGS. 49to 52.

FIG. 49 is a diagram for explaining the basic principle ofself-capacitance touch detection and illustrates a state where an objectto be detected is neither in contact with nor in proximity to adetection electrode. FIG. 50 is a diagram for explaining the basicprinciple of self-capacitance touch detection and illustrates a statewhere an object to be detected is in contact with or in proximity to thedetection electrode. FIG. 51 is a diagram for explaining an example ofan equivalent circuit in self-capacitance touch detection. FIG. 52 is adiagram of an example of waveforms of a drive signal and a detectionsignal in self-capacitance touch detection.

In the left figure in FIG. 49, an object to be detected is neither incontact with nor in proximity to a detection electrode, and a detectionelectrode E11 is coupled to a power source Vdd by a switch SW111 and isnot coupled to a capacitor Ccr by a switch SW112. In this state,capacitance Cx1 in the detection electrode E11 is charged. In the rightfigure in FIG. 49, coupling between the power source Vdd and thedetection electrode E11 is cut off by the switch SW111, and thedetection electrode E11 is coupled to the capacitor Ccr by the switchSW112. In this state, an electric charge of the capacitance Cx1 isdischarged via the capacitor Ccr.

In the left figure in FIG. 50, an object to be detected is in contactwith or in proximity to the detection electrode, and the detectionelectrode E11 is coupled to the power source Vdd by the switch SW111 andis not coupled to the capacitor Ccr by the switch SW112. In this state,capacitance Cx2 generated by the object to be detected in proximity tothe detection electrode E11 is also charged besides the capacitance Cx1in the detection electrode E11. In the right figure in FIG. 50, couplingbetween the power source Vdd and the detection electrode E11 is cut offby the switch SW111, and the detection electrode E11 is coupled to thecapacitor Ccr by the switch SW112. In this state, an electric charge ofthe capacitance Cx1 and an electric charge of the capacitance Cx2 aredischarged via the capacitor Ccr.

Because of the capacitance Cx2, the voltage change characteristics ofthe capacitor Ccr in discharging (the state where an object to bedetected is in contact with or in proximity to the detection electrode)illustrated in the right figure in FIG. 50 are clearly different fromthose of the capacitor Ccr in discharging (the state where an object tobe detected is neither in contact with nor in proximity to the detectionelectrode) illustrated in the right figure in FIG. 49. Consequently, inthe self-capacitance method, whether an object to be detected is incontact with or in proximity to the detection electrode is determinedusing the fact that the voltage change characteristics of the capacitorCcr vary depending on the presence of the capacitance Cx2.

Specifically, an AC rectangular wave Sg (corresponding to the touchdetection drive signal Vcomts, refer to FIG. 52) having a predeterminedfrequency (e.g., several kilohertz to several hundred kilohertz) isapplied to the detection electrode E11. A voltage detector DEillustrated in FIG. 51 converts fluctuations in the electric currentdepending on the AC rectangular wave Sg into fluctuations in the voltage(waveforms V₁₃ and V₁₄). The voltage detector DE corresponds to thedetection circuits INT₁₋₁, INT₁₋₂, . . . included in the COF 12illustrated in FIG. 48, for example. The voltage detector DE is thedetection circuit INT₁ or INT₂ illustrated in FIG. 17, for example.

As described above, the detection electrode E11 can be cut off fromanother element by the switch SW111 and the switch SW112. As illustratedin FIG. 52, the voltage level of the AC rectangular wave Sg rises to alevel corresponding to voltage V₁₀ at time T₀₁. At this time, the switchSW111 is in an on state, and the switch SW112 is in an off state. As aresult, the voltage of the detection electrode E11 also rises to voltageV₁₀.

Subsequently, the switch SW111 is turned off before time T₁₁. While thedetection electrode E11 is in a floating state at this time, theelectric potential of the detection electrode E11 is maintained at V₁₀by the capacitance Cx1 (refer to FIG. 49) of the detection electrode E11or capacitance (Cx1+Cx2, refer to FIG. 50) obtained by adding thecapacitance Cx2 to the capacitance Cx1 of the detection electrode E11,the capacitance Cx2 being generated by an object to be detected incontact with or in proximity to the detection electrode. Subsequently, aswitch SW113 is turned on before time T₁₁ and turned off after apredetermined time has elapsed, thereby resetting the voltage detectorDE. With this reset operation, the touch detection signal Vdet as theoutput voltage of the voltage detector DE is made substantially equal tothe reference potential Vref.

Subsequently, when the switch SW112 is turned on at time T₁₁, thevoltage of an inversion input end of the voltage detector DE rises tothe voltage V₁₀ equal to that of the detection electrode E11.Subsequently, the voltage of the inversion input end of the voltagedetector DE falls to the reference potential Vref according to a timeconstant of the capacitance Cx1 (or Cx1+Cx2) of the detection electrodeE11 and capacitance C5 in the voltage detector DE. At this time, theelectric charge accumulated in the capacitance Cx1 (or Cx1+Cx2) of thedetection electrode E11 moves to the capacitance C5 in the voltagedetector DE. As a result, a touch detection signal Vdet2 as the outputvoltage of the voltage detector DE rises.

When an object to be detected is not in proximity to the detectionelectrode E11, the touch detection signal Vdet2 as the output voltage ofthe voltage detector DE is represented by the waveform V₁₃ indicated bythe solid line, and Vdet2=Cx1 xV₁₀/C5 is satisfied.

When capacitance generated by an effect of an object to be detected isadded, the touch detection signal Vdet2 as the output voltage of thevoltage detector DE is represented by the waveform V₁₄ indicated by thedotted line, and Vdet2=(Cx1+Cx2)×V₁₀/C5 is satisfied. Subsequently, attime T₃₁ after the electric charge in the capacitance Cx1 (or Cx1+Cx2)of the detection electrode E11 sufficiently moves to the capacitance C5,the switch SW112 is turned off, and the switch SW111 and the switchSW113 are turned on. With this operation, the electric potential of thedetection electrode E11 is reduced to a low level equal to that of theAC rectangular wave Sg, and the voltage detector DE is reset. The timingto turn on the switch SW111 may be any timing after the turning off ofthe switch SW112 and before time T₀₂. The timing to reset the voltagedetector DE may be any timing after the turning off of the switch SW112and before time T₁₂.

The operation described above is repeated at a predetermined frequency(e.g., several kilohertz to several hundred kilohertz). As a result, itcan be determined whether an object to be detected is present (whether atouch is made) based on the absolute value |ΔV| of the differencebetween the waveform V₁₃ and the waveform V₁₄. As illustrated in FIG.52, when an object to be detected is not in contact with or in proximityto the detection electrode, the electric potential of the detectionelectrode E11 is represented by a waveform V₁₁. By contrast, when thecapacitance Cx2 generated by an effect of an object to be detected isadded, the electric potential is represented by a waveform V₁₂. It maybe determined whether an external proximity object is present (whether atouch is made) by measuring a time until when the waveforms V₁₁ and V₁₂fall to a predetermined threshold voltage VIE.

In the present embodiment, the drive electrodes COML of the panel PNLhare supplied with electric charges according to the touch detectiondrive signals Vcomts supplied from the drive electrode driver 9 h. Thedrive electrodes COML perform self-capacitance touch detection andoutput the touch detection signals Vdet2.

The drive electrodes COML according to the present embodiment correspondto the detector DET and the touch detector TDET (refer to FIG. 37).

Illustration and explanation of the flowchart of the operation performedby the display apparatus with a touch detection function according tothe seventh embodiment are omitted because it is the same as theflowchart (refer to FIG. 47) of the operation performed by the displayapparatus with a touch detection function 1 g according to the sixthembodiment.

The panel PNLh of the display apparatus with a touch detection functionaccording to the seventh embodiment is applicable to a lateral electricfield mode liquid crystal display apparatus (refer to FIG. 20) and to avertical electric field mode liquid crystal display apparatus.

The display apparatus with a touch detection function according to theseventh embodiment has the following characteristics besides thecharacteristics of the display apparatus according to the thirdembodiment. The display apparatus with a touch detection functionaccording to the seventh embodiment also has characteristics other thanthose described below. The display apparatus with a touch detectionfunction according to the seventh embodiment can perform touch detectionbesides image detection. The display apparatus may supply a positive-ornegative-polarity signal to at least one signal line SL and detect adetection signal with at least one drive electrode COML corresponding tothe at least one signal line SL supplied with the positive- ornegative-polarity signal.

8. Eighth Embodiment

FIG. 53 is a diagram of the module configuration of a display apparatuswith a touch detection function according to the eighth embodiment.

A panel PNLi includes a substrate 4 i, the drive electrode driver 9 g,and the COF 12 g. The substrate 4 i includes a first substrate 5 i and asecond substrate 6 i. The second substrate 6 i is disposed in theZ-direction with respect to the first substrate 5 i and faces the firstsubstrate 5 i with a predetermined space interposed therebetween.

The configuration of the panel PNLi of the display apparatus with atouch detection function according to the present embodiment isdifferent from that of the panel PNLd (refer to FIG. 22) of the displayapparatus according to the fourth embodiment in that the detection linesRL are provided to the second substrate 6 i. The detection lines RL arearranged one for every two rows of the pixels Pix and extend in theX-direction. In other words, the number of detection lines RL is (M/2).

FIG. 54 is a diagram of the configuration of the horizontal driver, thedrive electrode driver, and the COF of the display apparatus with atouch detection function according to the eighth embodiment. FIG. 54illustrates a portion of the horizontal driver 8 that drives the pixelsPix of four columns, a portion of the drive electrode driver 9 g thatdrives the pixels Pix of four columns, and a portion of the COF 12 gthat reads detection signals of the pixels Pix of four columns.

Explanation of the configuration of the drive electrode driver 9 g, theCOF 12 g, and the detection lines RL is omitted because it is the sameas that of the sixth embodiment (refer to FIG. 43).

The display apparatus with a touch detection function according to theeighth embodiment has the following characteristics besides thecharacteristics of the display apparatus according to the fourthembodiment. The display apparatus with a touch detection functionaccording to the eighth embodiment also has characteristics other thanthose described below. The display apparatus with a touch detectionfunction according to the eighth embodiment can perform touch detectionbesides image detection.

The display apparatus may supply a positive- or negative-polarity signalto at least one signal line SL and detect a detection signal with atleast one detection line RL corresponding to the at least one signalline SL supplied with the positive- or negative-polarity signal.

9. Ninth Embodiment

FIG. 55 is a block diagram of the configuration of a display apparatuswith a touch detection function according to a ninth embodiment.

The configuration of a display apparatus with a touch detection function1 j according to the present embodiment is different from that of thedisplay apparatus with a touch detection function 1 g according to thesixth embodiment in that a panel PNLj includes the display device DSPand the touch detector TDET. The display device DSP displays an image.The touch detector TDET detects contact or proximity of the object to bedetected OBJ with or to the touch detection surface IS. The detector DETis provided to the light emitter BL.

FIG. 56 is a diagram of the module configuration of the displayapparatus with a touch detection function according to the ninthembodiment.

The panel PNLj of the display apparatus with a touch detection function1 j according to the present embodiment includes a substrate 4 j. Thesubstrate 4 j includes a first substrate 5 j and a second substrate 6 j.The configuration of the panel PNLj is different from that of the panelPNLg (refer to FIG. 38) of the display apparatus according to the sixthembodiment in that the drive electrodes COML are not coupled to the COF12 g.

The detection lines RL according to the present embodiment correspond tothe touch detector TDET illustrated in FIG. 55.

Illustration and explanation of the configuration of the light emitterBL and the detector DET in the display apparatus with a touch detectionfunction 1 j according to the present embodiment are omitted because itis the same as that of the light emitter BL and the detector DET in thedisplay apparatus with a touch detection function if according to thefifth embodiment (refer to FIGS. 29 to 36).

The display apparatus with a touch detection function according to theninth embodiment has the following characteristics besides thecharacteristics of the display apparatus according to the fifthembodiment. The display apparatus with a touch detection functionaccording to the ninth embodiment can perform touch detection besidesimage detection.

The display apparatus may supply a positive- or negative-polarity signalto at least one signal line SL and detect a detection signal with atleast one detection line RL corresponding to the at least one signalline SL supplied with the positive- or negative-polarity signal.

While exemplary embodiments according to the present invention have beendescribed, the embodiments are not intended to limit the invention. Thecontents disclosed in the embodiments are given by way of example only,and various modifications may be made without departing from the spiritof the invention. Appropriate changes made without departing from thespirit of the invention naturally fall within the technical scope of theinvention.

What is claimed is:
 1. A control circuit for a display apparatuscomprising: a buffer configured to temporarily store thereinexternally-supplied image data; and a controller configured to outputpixel signals to signal lines of the display apparatus based on theimage data stored in the buffer and read detection signals generated indetection conductors which extend along the signal lines of the displayapparatus due to the pixel signals.
 2. A control circuit for a displayapparatus comprising: a buffer configured to temporarily store thereinexternally-supplied image data; and a controller configured to outputpixel signals to signal lines of the display apparatus based on theimage data stored in the buffer and read detection signals generated incommon electrodes of the display apparatus due to the pixel signals. 3.The control circuit for the display apparatus according to claim 2,wherein the common electrodes are disposed in a layer different from alayer of the signal lines and extend in an extending direction of thesignal lines.
 4. The control circuit for the display apparatus accordingto claim 3, wherein the common electrodes are disposed in a layerdifferent from a layer of the signal lines and disposed in a matrix in adisplay area provided with pixels.
 5. A control circuit for a displayapparatus comprising: a buffer configured to temporarily store thereinexternally-supplied image data; a controller configured to output pixelsignals to signal lines of the display apparatus based on the image datastored in the buffer and read detection signals generated in detectionconductors of the display apparatus due to the pixel signals; and atouch detector configured to detect contact or proximity of an object tobe detected.
 6. The control circuit for the display apparatus accordingto claim 5, wherein the detection conductors also serve as a pluralityof drive electrodes configured to generate an electric field on pixelsof the display apparatus and cause the pixels to display an image, andwherein the detection conductors also serve as a plurality of touchdrive electrodes configured to detect contact or proximity of the objectto be detected.
 7. The control circuit for the display apparatusaccording to claim 6, wherein the detection conductors are disposed in alayer different from a layer of the signal lines and extend in anextending direction of the signal lines.
 8. The control circuit for thedisplay apparatus according to claim 7, wherein the touch detectorincludes a plurality of touch detection lines extending in a directionintersecting the detection conductors, and wherein the controllerdetects contact or proximity of the object to be detected based onmutual capacitance between the detection conductors and the touchdetection lines.
 9. The control circuit for the display apparatusaccording to claim 6, wherein the detection conductors are disposed in alayer different from a layer of the signal lines and disposed in amatrix in a display area provided with the pixels.
 10. The controlcircuit for the display apparatus according to claim 9, wherein thecontroller detects contact or proximity of the object to be detectedbased on self-capacitance of the detection conductors.
 11. The controlcircuit for the display apparatus according to claim 5, wherein thedisplay apparatus further comprises a first substrate and a secondsubstrate facing the first substrate, wherein the signal lines areprovided to the first substrate, and wherein the detection conductorsare provided to the second substrate.
 12. The control circuit for thedisplay apparatus according to claim 7, wherein the display apparatusfurther comprises a first substrate and a second substrate facing thefirst substrate, and wherein the signal lines and the detectionconductors are provided to the first substrate.
 13. The control circuitfor the display apparatus according to claim 5, wherein the displayapparatus further comprises a light emitter configured to irradiatepixels, and wherein the detection conductors are provided on a firstside of the light emitter facing the pixels, on a second side of thelight emitter opposite to the first side, or in the light emitter. 14.The control circuit for the display apparatus according to claim 5,wherein a frame period for performing display and detection anddetecting a touch on one frame includes a plurality of horizontalperiods and a touch detection period, each horizontal period including adetection period and a display period, wherein the controller outputsthe pixel signals to the signal lines and reads the detection signals inthe detection period, and then outputs the pixel signals to the signallines and causes the pixels to perform display in the display period,and wherein the controller outputs touch detection signals to thedetection conductors and detects contact or proximity of the object tobe detected in the touch detection period.